diff --git a/src/addresses.h b/src/addresses.h
index d042c530d9..c59bb061a4 100644
--- a/src/addresses.h
+++ b/src/addresses.h
@@ -168,6 +168,14 @@
 #define RCT2_ADDRESS_CURRENT_WEATHER				0x013CA74A
 #define RCT2_ADDRESS_NEXT_WEATHER					0x013CA74B
 #define RCT2_ADDRESS_CURRENT_TEMPERATURE			0x013CA74C
+#define RCT2_ADDRESS_NEXT_TEMPERATURE				0x013CA74D
+#define RCT2_ADDRESS_CLIMATE_UPDATE_TIMER			0x013CA748
+#define RCT2_ADDRESS_CURRENT_WEATHER_EFFECT			0x013CA74E
+#define RCT2_ADDRESS_NEXT_WEATHER_EFFECT			0x013CA74F
+#define RCT2_ADDRESS_CURRENT_WEATHER_GLOOM			0x013CA750
+#define RCT2_ADDRESS_NEXT_WEATHER_GLOOM				0x013CA751
+#define RCT2_ADDRESS_CURRENT_RAIN_LEVEL				0x013CA752
+#define RCT2_ADDRESS_NEXT_RAIN_LEVEL				0x013CA753
 
 #define RCT2_ADDRESS_NEWS_ITEM_LIST					0x013CA754
 
diff --git a/src/climate.c b/src/climate.c
index 71ae908eda..dd2275be2a 100644
--- a/src/climate.c
+++ b/src/climate.c
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * Copyright (c) 2014 Ted John
+ * Copyright (c) 2014 Ted John, Matthias Lanzinger
  * OpenRCT2, an open source clone of Roller Coaster Tycoon 2.
  *
  * This file is part of OpenRCT2.
@@ -19,32 +19,234 @@
  *****************************************************************************/
 
 #include "addresses.h"
+#include "climate.h"
 #include "date.h"
+#include "gfx.h"
 #include "rct2.h"
 
+typedef struct {
+	sint8 base_temperature;
+	sint8 distribution_size;
+	sint8 distribution[24];
+} rct_weather_transition;
+
+int gClimateNextWeather;
+
+static int _climateNextTemperature;
+static int _climateNextWeatherEffect;
+static int _climateNextWeatherGloom;
+static int _climateNextRainLevel;
+
+static const rct_weather_transition* climate_transitions[4];
+
+static void climate_determine_future_weather();
+
 int climate_celcius_to_fahrenheit(int celcius)
 {
 	return (celcius * 29) / 16 + 32;
 }
 
 /**
- *
+ *  Set climate and determine start weather.
  *  rct2: 0x006C45ED
  */
 void climate_reset(int climate)
 {
-	int eax, ebx, ecx, edx, esi, edi, ebp;
-
 	RCT2_GLOBAL(RCT2_ADDRESS_CLIMATE, sint8) = climate;
-
-	eax = 1;
-	RCT2_CALLFUNC_X(0x006C4672, &eax, &ebx, &ecx, &edx, &esi, &edi, &ebp);
-
-	RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_WEATHER, sint8) = eax & 0xFF;
-	RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_TEMPERATURE, sint8) = ebx & 0xFF;
-
-	RCT2_GLOBAL(0x013CA74E, sint8) = (ebx >> 8) & 0xFF;
-	RCT2_GLOBAL(0x013CA750, sint8) = ecx & 0xFF;
-	RCT2_GLOBAL(0x013CA752, sint8) = (ecx >> 8) & 0xFF;
-	RCT2_CALLPROC_X(0x6C461C, 0, 0, 0, 0, 0, 0, 0);
+	climate_determine_future_weather();
 }
+
+
+/**
+ * Weather & climate update iteration.
+ * Gradually changes the weather parameters towards their determined next values.
+ * 
+ * rct2: 0x006C46B1
+ */
+void climate_update()
+{
+	uint8 screen_flags = RCT2_GLOBAL(RCT2_ADDRESS_SCREEN_FLAGS, uint8);
+	sint8 temperature = RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_TEMPERATURE, sint8),
+		target_temperature = _climateNextTemperature,
+		cur_gloom = RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_WEATHER_GLOOM, sint8),
+		next_gloom = _climateNextWeatherGloom,
+		cur_rain = RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_RAIN_LEVEL, sint8),
+		next_rain = _climateNextRainLevel;
+	
+
+	if (screen_flags & (~SCREEN_FLAGS_PLAYING)) // only normal play mode gets climate
+		return;
+
+	if (RCT2_GLOBAL(RCT2_ADDRESS_CLIMATE_UPDATE_TIMER, sint16))	{
+
+		if (RCT2_GLOBAL(RCT2_ADDRESS_CLIMATE_UPDATE_TIMER, sint16) == 960)
+			RCT2_GLOBAL(0x009A9804, uint32) |= 8; // climate dirty flag?
+
+		RCT2_GLOBAL(RCT2_ADDRESS_CLIMATE_UPDATE_TIMER, sint16)--;
+
+	} else if (!(RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_TICKS, sint32) & 0x7F)) {
+		
+		if (temperature == target_temperature) {
+			if (cur_gloom == next_gloom) {
+				RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_WEATHER_EFFECT, sint8) = _climateNextWeatherEffect;
+
+				if (cur_rain == next_rain) {
+					RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_WEATHER, sint8) = gClimateNextWeather;
+					climate_determine_future_weather();
+					RCT2_GLOBAL(0x009A9804, uint32) |= 8; // climate dirty flag?
+				} else {
+					if (next_rain == 3) {
+						cur_rain = 3;
+					} else {
+						sint8 next_rain_step = cur_rain + 1;
+						if (cur_rain > next_rain)
+							next_rain_step = cur_rain - 1;
+						RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_RAIN_LEVEL, sint8) = next_rain_step;
+					}
+				}
+			} else {
+				sint8 next_gloom_step = cur_gloom + 1;
+				if (cur_gloom > next_gloom)
+					next_gloom_step = cur_gloom - 1;
+
+				RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_WEATHER_GLOOM, sint8) = next_gloom_step;
+				gfx_invalidate_screen();
+			}
+
+		} else {
+			sint8 newtemp = temperature + 1;			
+			if (temperature > target_temperature)
+				newtemp = temperature - 1;
+
+			RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_TEMPERATURE, sint8) = newtemp;
+			RCT2_GLOBAL(0x009A9804, uint32) |= 8; // climate dirty flag?
+		}
+	}
+}
+
+
+/**
+ * Calculates future weather development.
+ * RCT2 implements this as discrete probability distributions dependant on month and climate 
+ * for next_weather. The other weather parameters are then looked up depending only on the
+ * next weather.
+ *
+ * rct2: 0x006C461C
+ */
+static void climate_determine_future_weather()
+{
+	sint8 climate = RCT2_GLOBAL(RCT2_ADDRESS_CLIMATE, sint8);
+	const rct_weather_transition* climate_table = climate_transitions[climate];
+	sint8 month = RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_MONTH_YEAR, sint16) & 7;
+	rct_weather_transition transition = climate_table[month];
+	
+	// Generate a random variable with values 0 upto distribution_size-1 and chose weather from the distribution table accordingly
+	sint8 next_weather = transition.distribution[ ((rand() & 0xFF) * transition.distribution_size) >> 8 ];
+	gClimateNextWeather = next_weather;
+
+	_climateNextTemperature = transition.base_temperature + climate_weather_data[next_weather].temp_delta;
+	_climateNextWeatherEffect = climate_weather_data[next_weather].effect_level;
+	_climateNextWeatherGloom = climate_weather_data[next_weather].gloom_level;
+	_climateNextRainLevel = climate_weather_data[next_weather].rain_level;
+	
+	RCT2_GLOBAL(RCT2_ADDRESS_CLIMATE_UPDATE_TIMER, sint16) = 1920;
+}
+
+
+
+#pragma region Climate / Weather data tables
+
+// rct2: 0x00993C94
+// There is actually a sprite at 0x5A9C for snow but only these weather types seem to be fully implemented
+const rct_weather climate_weather_data[6] = {
+	{ .temp_delta = 10, .effect_level = 0, .gloom_level = 0, .rain_level = 0, .sprite_id = 0x5A96 }, // Sunny
+	{ .temp_delta = 5, .effect_level = 0, .gloom_level = 0, .rain_level = 0, .sprite_id = 0x5A97 }, // Partially Cloudy
+	{ .temp_delta = 0, .effect_level = 0, .gloom_level = 0, .rain_level = 0, .sprite_id = 0x5A98 }, // Cloudy
+	{ .temp_delta = -2, .effect_level = 1, .gloom_level = 1, .rain_level = 1, .sprite_id = 0x5A99 }, // Rain
+	{ .temp_delta = -4, .effect_level = 1, .gloom_level = 2, .rain_level = 2, .sprite_id = 0x5A9A }, // Heavy Rain
+	{ .temp_delta = 2, .effect_level = 2, .gloom_level = 2, .rain_level = 2, .sprite_id = 0x5A9B }, // Thunderstorm
+};
+
+
+// rct2: 00993998
+static const rct_weather_transition climate_cool_and_wet_transitions[] = {
+	{ .base_temperature = 8, .distribution_size = 18,
+	.distribution = { 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 4, 4, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 10, .distribution_size = 21,
+	.distribution = { 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 0, 0 } },
+	{ .base_temperature = 14, .distribution_size = 17,
+	.distribution = { 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 17, .distribution_size = 17,
+	.distribution = { 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 19, .distribution_size = 23,
+	.distribution = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 4 } },
+	{ .base_temperature = 20, .distribution_size = 23,
+	.distribution = { 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 4, 4, 4, 5 } },
+	{ .base_temperature = 16, .distribution_size = 19,
+	.distribution = { 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 4, 4, 5, 0, 0, 0, 0 } },
+	{ .base_temperature = 13, .distribution_size = 16,
+	.distribution = { 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 4, 5, 0, 0, 0, 0, 0, 0, 0 } }
+};
+static const rct_weather_transition climate_warm_transitions[] = {
+	{ .base_temperature = 12, .distribution_size = 21,
+	.distribution = { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 4, 0, 0 } },
+	{ .base_temperature = 13, .distribution_size = 22,
+	.distribution = { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 5, 0 } },
+	{ .base_temperature = 16, .distribution_size = 17,
+	.distribution = { 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 19, .distribution_size = 18,
+	.distribution = { 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 21, .distribution_size = 22,
+	.distribution = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 0 } },
+	{ .base_temperature = 22, .distribution_size = 17,
+	.distribution = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 5, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 19, .distribution_size = 17,
+	.distribution = { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 16, .distribution_size = 17,
+	.distribution = { 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 0, 0, 0, 0, 0, 0 } }
+};
+static const rct_weather_transition climate_hot_and_dry_transitions[] = {
+	{ .base_temperature = 12, .distribution_size = 15,
+	.distribution = { 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 14, .distribution_size = 12,
+	.distribution = { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 16, .distribution_size = 11,
+	.distribution = { 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 19, .distribution_size = 9,
+	.distribution = { 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 21, .distribution_size = 13,
+	.distribution = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 22, .distribution_size = 11,
+	.distribution = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 21, .distribution_size = 12,
+	.distribution = { 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 16, .distribution_size = 13,
+	.distribution = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } }
+};
+static const rct_weather_transition climate_cold_transitions[] = {
+	{ .base_temperature = 4, .distribution_size = 18,
+	.distribution = { 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 3, 4, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 5, .distribution_size = 21,
+	.distribution = { 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 4, 5, 0, 0 } },
+	{ .base_temperature = 7, .distribution_size = 17,
+	.distribution = { 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 4, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 9, .distribution_size = 17,
+	.distribution = { 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 0, 0, 0, 0, 0, 0 } },
+	{ .base_temperature = 10, .distribution_size = 23,
+	.distribution = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 4 } },
+	{ .base_temperature = 11, .distribution_size = 23,
+	.distribution = { 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 4, 5 } },
+	{ .base_temperature = 9, .distribution_size = 19,
+	.distribution = { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 4, 5, 0, 0, 0, 0 } },
+	{ .base_temperature = 6, .distribution_size = 16,
+	.distribution = { 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 4, 5, 0, 0, 0, 0, 0, 0, 0 } }
+};
+
+static const rct_weather_transition* climate_transitions[] = {
+	climate_cool_and_wet_transitions,
+	climate_warm_transitions,
+	climate_hot_and_dry_transitions,
+	climate_cold_transitions
+};
+
+#pragma endregion
\ No newline at end of file
diff --git a/src/climate.h b/src/climate.h
index 7325bfd8b1..2c035b86f7 100644
--- a/src/climate.h
+++ b/src/climate.h
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * Copyright (c) 2014 Ted John
+ * Copyright (c) 2014 Ted John, Matthias Lanzinger
  * OpenRCT2, an open source clone of Roller Coaster Tycoon 2.
  *
  * This file is part of OpenRCT2.
@@ -21,6 +21,8 @@
 #ifndef _CLIMATE_H_
 #define _CLIMATE_H_
 
+#include "rct2.h"
+
 enum {
 	CLIMATE_COOL_AND_WET,
 	CLIMATE_WARM,
@@ -28,7 +30,19 @@ enum {
 	CLIMATE_COLD
 };
 
+typedef struct {
+	sint8 temp_delta;
+	sint8 effect_level;
+	sint8 gloom_level;
+	sint8 rain_level;
+	uint32 sprite_id;
+} rct_weather;
+
+extern int gClimateNextWeather;
+extern const rct_weather climate_weather_data[6];
+
 int climate_celcius_to_fahrenheit(int celcius);
 void climate_reset(int climate);
+void climate_update();
 
 #endif
diff --git a/src/game.c b/src/game.c
index 5e57312080..d5f909d3b1 100644
--- a/src/game.c
+++ b/src/game.c
@@ -20,6 +20,7 @@
  
 #include "addresses.h"
 #include "audio.h"
+#include "climate.h"
 #include "config.h"
 #include "rct2.h"
 #include "game.h"
@@ -128,7 +129,7 @@ void game_logic_update()
 {
 	short stringId, _dx;
 
-	RCT2_GLOBAL(0x013628F4, sint32)++;
+	RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_TICKS, sint32)++;
 	RCT2_GLOBAL(0x00F663AC, sint32)++;
 	RCT2_GLOBAL(0x009DEA66, sint16)++;
 	if (RCT2_GLOBAL(0x009DEA66, sint16) == 0)
@@ -136,7 +137,7 @@ void game_logic_update()
 
 	RCT2_CALLPROC_EBPSAFE(0x0068B089);
 	RCT2_CALLPROC_EBPSAFE(0x006C44B1);	// update_objective
-	RCT2_CALLPROC_EBPSAFE(0x006C46B1);	// update_climate
+	climate_update();
 	RCT2_CALLPROC_EBPSAFE(0x006646E1);
 	RCT2_CALLPROC_EBPSAFE(0x006A876D);
 	peep_update_all();
@@ -321,8 +322,8 @@ static void game_handle_input_mouse(int x, int y, int state)
 				RCT2_GLOBAL(RCT2_ADDRESS_INPUT_STATE, uint8) = INPUT_STATE_VIEWPORT_DRAG;
 				RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_DRAG_LAST_X, sint16) = x;
 				RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_DRAG_LAST_Y, sint16) = y;
-				RCT2_GLOBAL(0x009DE530, rct_windowclass) = w->classification;
-				RCT2_GLOBAL(0x009DE52E, rct_windownumber) = w->number;
+				RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_DRAG_WINDOWCLASS, rct_windowclass) = w->classification;
+				RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_DRAG_WINDOWNUMBER, rct_windownumber) = w->number;
 				RCT2_GLOBAL(0x009DE540, sint16) = 0;
 				// hide cursor
 				// RCT2_CALLPROC_X(0x00407045, 0, 0, 0, 0, 0, 0, 0);
@@ -384,7 +385,7 @@ static void game_handle_input_mouse(int x, int y, int state)
 		
 		dx = x - RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_DRAG_LAST_X, sint16);
 		dy = y - RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_DRAG_LAST_Y, sint16);
-		w = window_find_by_id(RCT2_GLOBAL(0x009DE530, rct_windowclass), RCT2_GLOBAL(0x009DE52E, rct_windownumber));
+		w = window_find_by_id(RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_DRAG_WINDOWCLASS, rct_windowclass), RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_DRAG_WINDOWNUMBER, rct_windownumber));
 		if (state == 0) {
 			rct_viewport *viewport = w->viewport;
 			RCT2_GLOBAL(0x009DE540, sint16) += RCT2_GLOBAL(0x009DE588, sint16);
@@ -908,7 +909,7 @@ void game_handle_keyboard_input()
 
 	// Handle mouse scrolling
 	if (RCT2_GLOBAL(RCT2_ADDRESS_ON_TUTORIAL, uint8) == 0)
-		if (RCT2_GLOBAL(0x009AACBA, uint8) != 0)
+		if (RCT2_GLOBAL(RCT2_ADDRESS_CONFIG_EDGE_SCROLLING, uint8) != 0)
 			if (RCT2_GLOBAL(RCT2_ADDRESS_INPUT_STATE, uint8) == 1)
 				if (!(RCT2_GLOBAL(RCT2_ADDRESS_PLACE_OBJECT_MODIFIER, uint8) & 3))
 					game_handle_edge_scroll();
diff --git a/src/gfx.c b/src/gfx.c
index 9cebbf2674..1a313818c3 100644
--- a/src/gfx.c
+++ b/src/gfx.c
@@ -243,7 +243,7 @@ void gfx_set_dirty_blocks(int left, int top, int right, int bottom)
 
 	for (y = top; y <= bottom; y++)
 		for (x = left; x <= right; x++)
-			screenDirtyBlocks[y * RCT2_GLOBAL(0x009ABDE8, sint32) + x] = 0xFF;
+			screenDirtyBlocks[y * RCT2_GLOBAL(RCT2_ADDRESS_DIRTY_BLOCK_COLUMNS, sint32) + x] = 0xFF;
 }
 
 /**
diff --git a/src/osinterface.c b/src/osinterface.c
index f2d0ff306a..2b2484f70c 100644
--- a/src/osinterface.c
+++ b/src/osinterface.c
@@ -72,8 +72,8 @@ static void osinterface_create_window()
 		RCT2_CALLPROC_EBPSAFE(0x0068352C);
 		RCT2_CALLPROC_EBPSAFE(0x0068371D);
 
-		width = RCT2_GLOBAL(0x009AB4C2, sint16);
-		height = RCT2_GLOBAL(0x009AB4C4, sint16);
+		width = RCT2_GLOBAL(RCT2_ADDRESS_CONFIG_RESOLUTION_WIDTH, sint16);
+		height = RCT2_GLOBAL(RCT2_ADDRESS_CONFIG_RESOLUTION_HEIGHT, sint16);
 
 		width = 640;
 		height = 480;
@@ -140,10 +140,10 @@ static void osinterface_resize(int width, int height)
 	RCT2_GLOBAL(0x009ABDF0, uint8) = 6;
 	RCT2_GLOBAL(0x009ABDF1, uint8) = 3;
 	RCT2_GLOBAL(0x009ABDF2, uint8) = 1;
-	RCT2_GLOBAL(0x009ABDE4, sint16) = 64;
-	RCT2_GLOBAL(0x009ABDE6, sint16) = 8;
-	RCT2_GLOBAL(0x009ABDE8, sint32) = (width >> 6) + 1;
-	RCT2_GLOBAL(0x009ABDEC, sint32) = (height >> 3) + 1;
+	RCT2_GLOBAL(RCT2_ADDRESS_DIRTY_BLOCK_WIDTH, sint16) = 64;
+	RCT2_GLOBAL(RCT2_ADDRESS_DIRTY_BLOCK_HEIGHT, sint16) = 8;
+	RCT2_GLOBAL(RCT2_ADDRESS_DIRTY_BLOCK_COLUMNS, sint32) = (width >> 6) + 1;
+	RCT2_GLOBAL(RCT2_ADDRESS_DIRTY_BLOCK_ROWS, sint32) = (height >> 3) + 1;
 
 	RCT2_CALLPROC_EBPSAFE(0x0066B905); // resize_gui()
 	gfx_invalidate_screen();
diff --git a/src/peep.c b/src/peep.c
index e50fb7c80a..0a16060ca2 100644
--- a/src/peep.c
+++ b/src/peep.c
@@ -60,7 +60,7 @@ void peep_update_all()
 		peep = &(RCT2_ADDRESS(RCT2_ADDRESS_SPRITE_LIST, rct_sprite)[sprite_index].peep);
 		sprite_index = peep->next;
 
-		if ((i & 0x7F) != (RCT2_GLOBAL(0x013628F4, uint32) & 0x7F)) {
+		if ((i & 0x7F) != (RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_TICKS, uint32) & 0x7F)) {
 			RCT2_CALLPROC_X(0x0068FC1E, 0, 0, 0, 0, peep, 0, 0);
 		} else {
 			RCT2_CALLPROC_X(0x0068F41A, 0, 0, 0, i, peep, 0, 0);
diff --git a/src/rct2.c b/src/rct2.c
index 64fd70c1a9..df687dca0c 100644
--- a/src/rct2.c
+++ b/src/rct2.c
@@ -103,8 +103,8 @@ void rct2_init()
 	RCT2_GLOBAL(0x00F663AC, int) = 0;
 	RCT2_GLOBAL(0x009AC310, char*) = RCT2_GLOBAL(RCT2_ADDRESS_CMDLINE, char*);
 	get_system_time();
-	RCT2_GLOBAL(0x009DEA69, short) = RCT2_GLOBAL(0x01424304, short);
-	RCT2_GLOBAL(0x009DEA6B, short) = RCT2_GLOBAL(0x01424304, short);
+	RCT2_GLOBAL(0x009DEA69, short) = RCT2_GLOBAL(RCT2_ADDRESS_OS_TIME_DAY, short);
+	RCT2_GLOBAL(0x009DEA6B, short) = RCT2_GLOBAL(RCT2_ADDRESS_OS_TIME_DAY, short);
 	rct2_init_directories();
 	rct2_startup_checks();
 	config_reset_shortcut_keys();
diff --git a/src/scenario.c b/src/scenario.c
index 61b9108483..6eee3c4849 100644
--- a/src/scenario.c
+++ b/src/scenario.c
@@ -424,7 +424,7 @@ void scenario_load_and_play(rct_scenario_basic *scenario)
 
 	uint8 _cl = (RCT2_GLOBAL(0x0138869E, sint16) & 0xFF) - mainWindow->viewport->zoom;
 	mainWindow->viewport->zoom = RCT2_GLOBAL(0x0138869E, sint16) & 0xFF;
-	*((char*)(&RCT2_GLOBAL(0x0141E9E0, sint32))) = RCT2_GLOBAL(0x0138869E, sint16) >> 8;
+	*((char*)(&RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_ROTATION, sint32))) = RCT2_GLOBAL(0x0138869E, sint16) >> 8;
 	if (_cl != 0) {
 		if (_cl < 0) {
 			_cl = -_cl;
@@ -451,7 +451,7 @@ void scenario_load_and_play(rct_scenario_basic *scenario)
 	RCT2_CALLPROC_EBPSAFE(0x00684AC3);
 	RCT2_CALLPROC_EBPSAFE(0x006DFEE4);
 	news_item_init_queue();
-	if (RCT2_ADDRESS(0x013580F8, uint8) != OBJECTIVE_NONE)
+	if (RCT2_ADDRESS(RCT2_ADDRESS_OBJECTIVE_TYPE, uint8) != OBJECTIVE_NONE)
 		window_park_objective_open();
 
 	RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_PARK_RATING, sint16) = calculate_park_rating();
diff --git a/src/title.c b/src/title.c
index 6eb9fd77c7..5b447bca8a 100644
--- a/src/title.c
+++ b/src/title.c
@@ -172,7 +172,7 @@ static void title_update_showcase()
 				{
 					char _cl = (RCT2_GLOBAL(0x0138869E, sint16) & 0xFF) - w->viewport->zoom;
 					w->viewport->zoom = RCT2_GLOBAL(0x0138869E, sint16) & 0xFF;
-					*((char*)(&RCT2_GLOBAL(0x0141E9E0, sint32))) = RCT2_GLOBAL(0x0138869E, sint16) >> 8;
+					*((char*)(&RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_ROTATION, sint32))) = RCT2_GLOBAL(0x0138869E, sint16) >> 8;
 					if (_cl != 0) {
 						if (_cl < 0) {
 							_cl = -_cl;
diff --git a/src/window_clear_scenery.c b/src/window_clear_scenery.c
index 567a9358f8..061de23294 100644
--- a/src/window_clear_scenery.c
+++ b/src/window_clear_scenery.c
@@ -226,9 +226,9 @@ static int window_clear_scenery_should_close()
 {
 	if (!(RCT2_GLOBAL(0x009DE518, uint32) & (1 << 3)))
 		return 1;
-	if (RCT2_GLOBAL(0x009DE544, rct_windowclass) != WC_TOP_TOOLBAR)
+	if (RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WINDOWCLASS, rct_windowclass) != WC_TOP_TOOLBAR)
 		return 1;
-	if (RCT2_GLOBAL(0x009DE546, uint16) != 16)
+	if (RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WIDGETINDEX, uint16) != 16)
 		return 1;
 	return 0;
 }
diff --git a/src/window_dropdown.c b/src/window_dropdown.c
index 0aecd65450..9050dd6c64 100644
--- a/src/window_dropdown.c
+++ b/src/window_dropdown.c
@@ -108,7 +108,7 @@ void window_dropdown_show_text(int x, int y, int extray, uint8 colour, uint8 fla
 	max_string_width = 0;
 	for (i = 0; i < num_items; i++) {
 		format_string(buffer, gDropdownItemsFormat[i], (void*)(&gDropdownItemsArgs[i]));
-		RCT2_GLOBAL(0x013CE950, sint16) = 224;
+		RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_FONT_SPRITE_BASE, sint16) = 224;
 		string_width = gfx_get_string_width(buffer);
 		max_string_width = max(string_width, max_string_width);
 	}
diff --git a/src/window_game_bottom_toolbar.c b/src/window_game_bottom_toolbar.c
index 9723e30a65..c161165956 100644
--- a/src/window_game_bottom_toolbar.c
+++ b/src/window_game_bottom_toolbar.c
@@ -390,7 +390,7 @@ static void window_game_bottom_toolbar_draw_left_panel(rct_drawpixelinfo *dpi, r
 			dpi,
 			(*((int*)0x013CE952) < 0 ? 1391 : 1390),
 			x, y - 3,
-			(RCT2_GLOBAL(0x009DE55C, rct_windowclass) == 2 && RCT2_GLOBAL(0x009DE560, sint32) == WIDX_MONEY ? 2 : w->colours[0] & 0x7F),
+			(RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_OVER_WINDOWCLASS, rct_windowclass) == 2 && RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_OVER_WIDGETINDEX, sint32) == WIDX_MONEY ? 2 : w->colours[0] & 0x7F),
 			(void*)0x013CE952
 			);
 		y += 7;
@@ -401,7 +401,7 @@ static void window_game_bottom_toolbar_draw_left_panel(rct_drawpixelinfo *dpi, r
 		dpi,
 		STR_NUM_GUESTS + RCT2_GLOBAL(0x013573FE, uint8),
 		x, y,
-		(RCT2_GLOBAL(0x009DE55C, rct_windowclass) == 2 && RCT2_GLOBAL(0x009DE560, sint32) == WIDX_GUESTS ? 2 : w->colours[0] & 0x7F),
+		(RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_OVER_WINDOWCLASS, rct_windowclass) == 2 && RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_OVER_WIDGETINDEX, sint32) == WIDX_GUESTS ? 2 : w->colours[0] & 0x7F),
 		(void*)0x01357844
 	);
 
@@ -426,7 +426,7 @@ static void window_game_bottom_toolbar_draw_park_rating(rct_drawpixelinfo *dpi,
 
 	bar_width = (factor * 90) / 256;
 	gfx_fill_rect_inset(dpi, x, y + 1, x + 93, y + 9, w->colours[1], 48);
-	if (!(colour & 0x80000000) || RCT2_GLOBAL(0x009DEA6E, uint8) != 0 || (RCT2_GLOBAL(0x013628F4, uint8) & 8)) {
+	if (!(colour & 0x80000000) || RCT2_GLOBAL(0x009DEA6E, uint8) != 0 || (RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_TICKS, uint8) & 8)) {
 		if (bar_width > 2)
 			gfx_fill_rect_inset(dpi, x + 2, y + 2, x + bar_width - 1, y + 8, colour & 0x7FFFFFFF, 0);
 	}
@@ -461,7 +461,7 @@ static void window_game_bottom_toolbar_draw_right_panel(rct_drawpixelinfo *dpi,
 		1845,
 		x,
 		y,
-		(RCT2_GLOBAL(0x009DE55C, rct_windowclass) == 2 && RCT2_GLOBAL(0x009DE560, sint32) == WIDX_DATE ? 2 : w->colours[0] & 0x7F),
+		(RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_OVER_WINDOWCLASS, rct_windowclass) == 2 && RCT2_GLOBAL(RCT2_ADDRESS_CURSOR_OVER_WIDGETINDEX, sint32) == WIDX_DATE ? 2 : w->colours[0] & 0x7F),
 		(void*)0x013CE952
 	);
 
@@ -480,13 +480,13 @@ static void window_game_bottom_toolbar_draw_right_panel(rct_drawpixelinfo *dpi,
 	x += 30;
 
 	// Current weather
-	gfx_draw_sprite(dpi, ((int*)0x00993C98)[RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_WEATHER, sint8) * 2], x, y);
+	gfx_draw_sprite(dpi, climate_weather_data[RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_WEATHER, sint8)].sprite_id, x, y);
 
 	// Next weather
-	if (((int*)0x00993C98)[RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_WEATHER, sint8) * 2] != ((int*)0x00993C98)[RCT2_GLOBAL(RCT2_ADDRESS_NEXT_WEATHER, sint8) * 2]) {
-		if (RCT2_GLOBAL(0x013CA748, sint16) < 960) {
+	if (climate_weather_data[RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_WEATHER, sint8)].sprite_id != climate_weather_data[gClimateNextWeather].sprite_id) {
+		if (RCT2_GLOBAL(RCT2_ADDRESS_CLIMATE_UPDATE_TIMER, sint16) < 960) {
 			gfx_draw_sprite(dpi, SPR_NEXT_WEATHER, x + 27, y + 5);
-			gfx_draw_sprite(dpi, ((int*)0x00993C98)[RCT2_GLOBAL(RCT2_ADDRESS_NEXT_WEATHER, sint8) * 2], x + 40, y);
+			gfx_draw_sprite(dpi, climate_weather_data[gClimateNextWeather].sprite_id, x + 40, y);
 		}
 	}
 }
diff --git a/src/window_game_top_toolbar.c b/src/window_game_top_toolbar.c
index a0527fba7c..020afbb811 100644
--- a/src/window_game_top_toolbar.c
+++ b/src/window_game_top_toolbar.c
@@ -174,7 +174,7 @@ static void window_game_top_toolbar_mouseup()
 		break;
 
 	case WIDX_CLEAR_SCENERY:
-		if ((RCT2_GLOBAL(0x009DE518, uint32) & (1 << 3)) && RCT2_GLOBAL(0x009DE544, uint8) == 1 && RCT2_GLOBAL(0x009DE546, uint16) == 16) {
+		if ((RCT2_GLOBAL(0x009DE518, uint32) & (1 << 3)) && RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WINDOWCLASS, uint8) == 1 && RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WIDGETINDEX, uint16) == 16) {
 			RCT2_CALLPROC_EBPSAFE(0x006EE281);
 		} else {
 			show_gridlines();
@@ -185,7 +185,7 @@ static void window_game_top_toolbar_mouseup()
 		}
 		break;
 	case WIDX_LAND:
-		if ((RCT2_GLOBAL(0x009DE518, uint32) & (1 << 3)) && RCT2_GLOBAL(0x009DE544, uint8) == 1 && RCT2_GLOBAL(0x009DE546, uint16) == 7) {
+		if ((RCT2_GLOBAL(0x009DE518, uint32) & (1 << 3)) && RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WINDOWCLASS, uint8) == 1 && RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WIDGETINDEX, uint16) == 7) {
 			RCT2_CALLPROC_EBPSAFE(0x006EE281);
 		} else {
 			show_gridlines();
@@ -196,7 +196,7 @@ static void window_game_top_toolbar_mouseup()
 		}
 		break;
 	case WIDX_WATER:
-		if ((RCT2_GLOBAL(0x009DE518, uint32) & (1 << 3)) && RCT2_GLOBAL(0x009DE544, uint8) == 1 && RCT2_GLOBAL(0x009DE546, uint16) == 8) {
+		if ((RCT2_GLOBAL(0x009DE518, uint32) & (1 << 3)) && RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WINDOWCLASS, uint8) == 1 && RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WIDGETINDEX, uint16) == 8) {
 			RCT2_CALLPROC_EBPSAFE(0x006EE281);
 		} else {
 			show_gridlines();
@@ -378,7 +378,7 @@ static void window_game_top_toolbar_dropdown()
 			RCT2_CALLPROC_EBPSAFE(0x006BAC5B);
 			break;
 		case 5:		// screenshot
-			RCT2_GLOBAL(0x009DEA6D, sint8) = 10;
+			RCT2_GLOBAL(RCT2_ADDRESS_SCREENSHOT_COUNTDOWN, sint8) = 10;
 			break;
 		case 7:		// quit game
 			RCT2_CALLPROC_X(0x006677F2, 0, 1, 0, 0, 5, 1, 0);
diff --git a/src/window_land.c b/src/window_land.c
index 46db92465c..0c196b46f1 100644
--- a/src/window_land.c
+++ b/src/window_land.c
@@ -137,8 +137,8 @@ void window_land_open()
 	RCT2_GLOBAL(RCT2_ADDRESS_SELECTED_TERRAIN_EDGE, uint8) = 255;
 	_selectedFloorTexture = 0;
 	_selectedWallTexture = 0;
-	RCT2_GLOBAL(0x009E2E1C, sint32) = 0x80000000;
-	RCT2_GLOBAL(0x009E2E20, sint32) = 0x80000000;
+	RCT2_GLOBAL(RCT2_ADDRESS_LAND_RAISE_COST, sint32) = 0x80000000;
+	RCT2_GLOBAL(RCT2_ADDRESS_LAND_LOWER_COST, sint32) = 0x80000000;
 	window->colours[0] = 24;
 	window->colours[1] = 24;
 	window->colours[2] = 24;
@@ -405,9 +405,9 @@ static int window_land_should_close()
 {
 	if (!(RCT2_GLOBAL(0x009DE518, uint32) & (1 << 3)))
 		return 1;
-	if (RCT2_GLOBAL(0x009DE544, rct_windowclass) != WC_TOP_TOOLBAR)
+	if (RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WINDOWCLASS, rct_windowclass) != WC_TOP_TOOLBAR)
 		return 1;
-	if (RCT2_GLOBAL(0x009DE546, sint16) != 7)
+	if (RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WIDGETINDEX, sint16) != 7)
 		return 1;
 	return 0;
 }
diff --git a/src/window_main.c b/src/window_main.c
index ba79333998..2c95d7cbc8 100644
--- a/src/window_main.c
+++ b/src/window_main.c
@@ -63,7 +63,7 @@ void window_main_open()
 		or word ptr [edi+12h], 400h
 	}
 	
-	RCT2_GLOBAL(0x0141E9E0, sint32) = 0;
+	RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_ROTATION, sint32) = 0;
 	RCT2_GLOBAL(0x009E32B0, uint8) = 0;
 	RCT2_GLOBAL(0x009E32B2, uint8) = 0;
 	RCT2_GLOBAL(0x009E32B3, uint8) = 0;
diff --git a/src/window_park.c b/src/window_park.c
index 8480be7627..84550d2026 100644
--- a/src/window_park.c
+++ b/src/window_park.c
@@ -644,7 +644,7 @@ static void window_park_entrance_close()
 	__asm mov w, esi
 
 	if (RCT2_GLOBAL(0x009DE518, uint32) & (1 << 3))
-		if (w->classification == RCT2_GLOBAL(0x009DE544, rct_windowclass) && w->number == RCT2_GLOBAL(0x009DE542, rct_windownumber))
+		if (w->classification == RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WINDOWCLASS, rct_windowclass) && w->number == RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WINDOWNUMBER, rct_windownumber))
 			RCT2_CALLPROC_EBPSAFE(0x006EE281);
 }
 
@@ -1617,7 +1617,7 @@ void window_park_objective_open()
 	}
 
 	if (RCT2_GLOBAL(0x009DE518, uint32) & (1 << 3))
-		if (window->classification == RCT2_GLOBAL(0x009DE544, rct_windowclass) && window->number == RCT2_GLOBAL(0x009DE542, rct_windownumber))
+		if (window->classification == RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WINDOWCLASS, rct_windowclass) && window->number == RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WINDOWNUMBER, rct_windownumber))
 			RCT2_CALLPROC_EBPSAFE(0x006EE281);
 
 	window->viewport = NULL;
diff --git a/src/window_water.c b/src/window_water.c
index fa0a0c12c2..6b7eab58a5 100644
--- a/src/window_water.c
+++ b/src/window_water.c
@@ -232,9 +232,9 @@ static int window_water_should_close()
 {
 	if (!(RCT2_GLOBAL(0x009DE518, uint32) & (1 << 3)))
 		return 1;
-	if (RCT2_GLOBAL(0x009DE544, rct_windowclass) != WC_TOP_TOOLBAR)
+	if (RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WINDOWCLASS, rct_windowclass) != WC_TOP_TOOLBAR)
 		return 1;
-	if (RCT2_GLOBAL(0x009DE546, uint16) != 8)
+	if (RCT2_GLOBAL(RCT2_ADDRESS_TOOL_WIDGETINDEX, uint16) != 8)
 		return 1;
 	return 0;
 }