diff --git a/asm/code_807E5AC.s b/asm/code_807E5AC.s
index 91304f75e..814e560e5 100644
--- a/asm/code_807E5AC.s
+++ b/asm/code_807E5AC.s
@@ -5,313 +5,8 @@
 
   	.text
 
-	thumb_func_start sub_807E698
-sub_807E698:
-	push {r4-r7,lr}
-	mov r7, r10
-	mov r6, r9
-	mov r5, r8
-	push {r5-r7}
-	sub sp, 0xC
-	lsls r0, 24
-	lsrs r0, 24
-	str r0, [sp]
-	movs r0, 0
-	bl GetApparentWeather
-	lsls r0, 24
-	lsrs r0, 16
-	str r0, [sp, 0x4]
-	ldr r0, _0807E724
-	ldr r0, [r0]
-	ldr r0, [r0, 0x4]
-	mov r10, r0
-	movs r0, 0
-	bl GetApparentWeather
-	lsls r0, 24
-	lsrs r0, 24
-	ldr r1, [sp]
-	bl sub_8042818
-	movs r0, 0x25
-	bl sub_803E46C
-	movs r0, 0x1
-	bl sub_804178C
-	ldr r1, _0807E728
-	ldrb r0, [r1]
-	str r0, [sp, 0x8]
-	movs r0, 0x1
-	strb r0, [r1]
-	movs r1, 0
-	mov r9, r1
-	ldr r2, _0807E72C
-	mov r8, r2
-_0807E6EC:
-	movs r7, 0
-	movs r0, 0x25
-	bl sub_803E46C
-	movs r6, 0
-	ldr r1, [sp, 0x4]
-	lsls r0, r1, 2
-	mov r2, r10
-	adds r5, r0, r2
-	movs r0, 0xFF
-	mov r12, r0
-_0807E702:
-	mov r1, r8
-	ldr r0, [r1]
-	adds r0, r6
-	movs r2, 0xBE
-	lsls r2, 1
-	adds r4, r0, r2
-	ldrb r0, [r4]
-	ldrb r3, [r5]
-	subs r1, r0, r3
-	cmp r1, 0
-	bge _0807E71A
-	negs r1, r1
-_0807E71A:
-	cmp r1, 0x9
-	bgt _0807E730
-	strb r3, [r4]
-	b _0807E746
-	.align 2, 0
-_0807E724: .4byte gUnknown_202ECA0
-_0807E728: .4byte gUnknown_203B40D
-_0807E72C: .4byte gDungeon
-_0807E730:
-	movs r7, 0x1
-	adds r2, r0, 0
-	adds r1, r3, 0
-	cmp r2, r1
-	bcs _0807E73E
-	adds r0, 0xA
-	b _0807E744
-_0807E73E:
-	cmp r2, r1
-	bls _0807E746
-	subs r0, 0xA
-_0807E744:
-	strb r0, [r4]
-_0807E746:
-	mov r1, r8
-	ldr r0, [r1]
-	adds r0, r6
-	ldr r2, _0807E764
-	adds r4, r0, r2
-	ldrb r0, [r4]
-	ldrb r3, [r5, 0x1]
-	subs r1, r0, r3
-	cmp r1, 0
-	bge _0807E75C
-	negs r1, r1
-_0807E75C:
-	cmp r1, 0x9
-	bgt _0807E768
-	strb r3, [r4]
-	b _0807E77E
-	.align 2, 0
-_0807E764: .4byte 0x0000017d
-_0807E768:
-	movs r7, 0x1
-	adds r2, r0, 0
-	adds r1, r3, 0
-	cmp r2, r1
-	bcs _0807E776
-	adds r0, 0xA
-	b _0807E77C
-_0807E776:
-	cmp r2, r1
-	bls _0807E77E
-	subs r0, 0xA
-_0807E77C:
-	strb r0, [r4]
-_0807E77E:
-	mov r1, r8
-	ldr r0, [r1]
-	adds r0, r6
-	movs r2, 0xBF
-	lsls r2, 1
-	adds r4, r0, r2
-	ldrb r0, [r4]
-	ldrb r3, [r5, 0x2]
-	subs r1, r0, r3
-	cmp r1, 0
-	bge _0807E796
-	negs r1, r1
-_0807E796:
-	cmp r1, 0x9
-	bgt _0807E79E
-	strb r3, [r4]
-	b _0807E7B4
-_0807E79E:
-	movs r7, 0x1
-	adds r2, r0, 0
-	adds r1, r3, 0
-	cmp r2, r1
-	bcs _0807E7AC
-	adds r0, 0xA
-	b _0807E7B2
-_0807E7AC:
-	cmp r2, r1
-	bls _0807E7B4
-	subs r0, 0xA
-_0807E7B2:
-	strb r0, [r4]
-_0807E7B4:
-	adds r6, 0x4
-	adds r5, 0x4
-	movs r0, 0x1
-	negs r0, r0
-	add r12, r0
-	mov r1, r12
-	cmp r1, 0
-	bge _0807E702
-	movs r0, 0
-	movs r1, 0
-	bl sub_803E874
-	cmp r7, 0
-	beq _0807E7DA
-	movs r2, 0x1
-	add r9, r2
-	mov r0, r9
-	cmp r0, 0x3F
-	ble _0807E6EC
-_0807E7DA:
-	ldr r0, _0807E7F8
-	mov r1, sp
-	ldrb r1, [r1, 0x8]
-	strb r1, [r0]
-	ldr r0, [sp]
-	bl sub_807E7FC
-	add sp, 0xC
-	pop {r3-r5}
-	mov r8, r3
-	mov r9, r4
-	mov r10, r5
-	pop {r4-r7}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0807E7F8: .4byte gUnknown_203B40D
-	thumb_func_end sub_807E698
 
-	thumb_func_start sub_807E7FC
-sub_807E7FC:
-	push {r4-r6,lr}
-	lsls r0, 24
-	lsrs r4, r0, 24
-	ldr r6, _0807E874
-	ldr r0, [r6]
-	ldr r1, _0807E878
-	adds r0, r1
-	ldr r5, [r0]
-	cmp r5, 0
-	bne _0807E816
-	bl GetLeader
-	adds r5, r0, 0
-_0807E816:
-	cmp r4, 0
-	beq _0807E844
-	ldr r0, [r6]
-	ldr r2, _0807E87C
-	adds r0, r2
-	ldrb r0, [r0]
-	cmp r0, 0
-	bne _0807E844
-	ldr r4, _0807E880
-	movs r0, 0
-	bl GetApparentWeather
-	adds r1, r0, 0
-	lsls r1, 24
-	lsrs r1, 24
-	adds r0, r4, 0
-	bl GetWeatherName
-	ldr r0, _0807E884
-	ldr r1, [r0]
-	adds r0, r5, 0
-	bl LogMessageByIdWithPopupCheckUser
-_0807E844:
-	movs r5, 0
-_0807E846:
-	ldr r0, _0807E874
-	ldr r0, [r0]
-	lsls r1, r5, 2
-	ldr r2, _0807E888
-	adds r0, r2
-	adds r0, r1
-	ldr r4, [r0]
-	adds r0, r4, 0
-	bl EntityExists
-	lsls r0, 24
-	cmp r0, 0
-	beq _0807E866
-	adds r0, r4, 0
-	bl sub_807E8F0
-_0807E866:
-	adds r5, 0x1
-	cmp r5, 0x13
-	ble _0807E846
-	pop {r4-r6}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0807E874: .4byte gDungeon
-_0807E878: .4byte 0x000181f8
-_0807E87C: .4byte 0x0001356c
-_0807E880: .4byte gFormatBuffer_Monsters
-_0807E884: .4byte gUnknown_80FC5E0
-_0807E888: .4byte 0x000135cc
-	thumb_func_end sub_807E7FC
 
-	thumb_func_start sub_807E88C
-sub_807E88C:
-	push {r4-r7,lr}
-	movs r0, 0
-	bl GetApparentWeather
-	lsls r0, 24
-	ldr r1, _0807E8E4
-	ldr r1, [r1]
-	ldr r1, [r1, 0x4]
-	movs r4, 0
-	ldr r5, _0807E8E8
-	lsrs r0, 14
-	adds r3, r0, r1
-	movs r6, 0xBE
-	lsls r6, 1
-_0807E8A8:
-	ldr r0, [r5]
-	lsls r2, r4, 2
-	adds r0, r2
-	ldrb r1, [r3]
-	adds r0, r6
-	strb r1, [r0]
-	ldr r0, [r5]
-	adds r0, r2
-	ldrb r1, [r3, 0x1]
-	ldr r7, _0807E8EC
-	adds r0, r7
-	strb r1, [r0]
-	ldr r0, [r5]
-	adds r0, r2
-	ldrb r1, [r3, 0x2]
-	movs r2, 0xBF
-	lsls r2, 1
-	adds r0, r2
-	strb r1, [r0]
-	adds r3, 0x4
-	adds r4, 0x1
-	cmp r4, 0xFF
-	ble _0807E8A8
-	movs r0, 0
-	movs r1, 0
-	bl sub_803E874
-	pop {r4-r7}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0807E8E4: .4byte gUnknown_202ECA0
-_0807E8E8: .4byte gDungeon
-_0807E8EC: .4byte 0x0000017d
-	thumb_func_end sub_807E88C
 
 	thumb_func_start sub_807E8F0
 sub_807E8F0:
@@ -363,7 +58,7 @@ _0807E90E:
 	strb r1, [r7]
 	b _0807E984
 	.align 2, 0
-_0807E954: .4byte gUnknown_80F520C
+_0807E954: .4byte gCastformByWeather
 _0807E958:
 	adds r0, r4, 0
 	adds r0, 0xC4
diff --git a/data/data_80F4E2C.s b/data/data_80F4E2C.s
index a95b7e466..d7a7917c0 100644
--- a/data/data_80F4E2C.s
+++ b/data/data_80F4E2C.s
@@ -809,8 +809,8 @@ gUnknown_80F51EC: @ 80F51EC
 .4byte 512
 .4byte 512
 
-	.global gUnknown_80F520C
-gUnknown_80F520C: @ 80F520C
+	.global gCastformByWeather
+gCastformByWeather: @ 80F520C
 @ replacing .incbin "baserom.gba", 0x000f520c, 0x20
 .byte 0x01, 0x00, 0x78, 0x01
 .byte  0x02, 0x00, 0x7a, 0x01
diff --git a/include/constants/weather.h b/include/constants/weather.h
index 2a8cf42ee..688e1100a 100644
--- a/include/constants/weather.h
+++ b/include/constants/weather.h
@@ -9,6 +9,6 @@
 #define WEATHER_HAIL                    5
 #define WEATHER_FOG                     6
 #define WEATHER_SNOW                    7
-#define WEATHER_RANDOM                  8
+#define WEATHER_COUNT                   8
 
 #endif // GUARD_CONSTANTS_WEATHER_H
diff --git a/include/structs/str_dungeon.h b/include/structs/str_dungeon.h
index 3ecb838a3..c751ce3a0 100644
--- a/include/structs/str_dungeon.h
+++ b/include/structs/str_dungeon.h
@@ -328,6 +328,8 @@ typedef struct unkDungeon57C
     s32 unk40;
 } unkDungeon57C;
 
+#define COLOR_RAMP_COUNT 256
+
 // size: 0x1CEDC
 typedef struct Dungeon
 {
@@ -357,7 +359,7 @@ typedef struct Dungeon
     Entity *unkBC;
     u8 fillC0[0x134 - 0xC0];
     struct unkStruct_Dungeon134_sub unk134;
-    /* 0x47C */ RGB colorRamp[0x100];
+    /* 0x17C */ RGB colorRamp[COLOR_RAMP_COUNT];
     /* 0x57C */ unkDungeon57C unk57C;
     /* 0x5C0 */ s32 unk5C0;
     /* 0x5C4 */ struct unkStruct_Dungeon5C4_sub unk5C4[3];
diff --git a/ld_script.txt b/ld_script.txt
index 5d27fce8b..5b6924e3c 100755
--- a/ld_script.txt
+++ b/ld_script.txt
@@ -266,6 +266,7 @@ SECTIONS {
         src/code_807CD9C.o(.text);
         src/code_807E1A0.o(.text);
         src/weather.o(.text);
+        src/code_807E5AC.o(.text);
         asm/code_807E5AC.o(.text);
         src/trap.o(.text);
         asm/code_807FCD4.o(.text);
diff --git a/src/code_8069E0C.c b/src/code_8069E0C.c
index ffe3ae31e..ebfa049f4 100644
--- a/src/code_8069E0C.c
+++ b/src/code_8069E0C.c
@@ -41,15 +41,13 @@
 #include "structs/str_806B7F8.h"
 #include "structs/str_202ED28.h"
 
-struct unkStruct_80F520C
+struct CastformWeatherData
 {
-    u8 unk0; // types0
-    u8 unk1; // Most likely just padding and should be removed
-    s16 unk2; // monsterID
+    u8 type;
+    s16 monsterId;
 };
 
-// Castform Forecast ability data
-extern const struct unkStruct_80F520C gUnknown_80F520C[WEATHER_RANDOM];
+extern const struct CastformWeatherData gCastformByWeather[WEATHER_COUNT];
 
 extern u8 gUnknown_80F51E4[];
 extern u8 *gUnknown_80FCC7C[];
@@ -109,7 +107,7 @@ void sub_8069E0C(Entity *pokemon)
 
   entityInfo = GetEntInfo(pokemon);
   if (AbilityIsActive(pokemon, ABILITY_FORECAST)) {
-    entityInfo->types[0] = gUnknown_80F520C[GetApparentWeather(pokemon)].unk0;
+    entityInfo->types[0] = gCastformByWeather[GetApparentWeather(pokemon)].type;
     entityInfo->types[1] = TYPE_NONE;
   }
   else {
@@ -156,7 +154,7 @@ s32 GetMonsterApparentID(Entity *pokemon, s32 _id)
     s16 id = (s16)(_id);
     if (id == MONSTER_CASTFORM || IS_CASTFORM_FORM_MONSTER(id)) {
         if (AbilityIsActive(pokemon, ABILITY_FORECAST))
-            return gUnknown_80F520C[GetApparentWeather(pokemon)].unk2;
+            return gCastformByWeather[GetApparentWeather(pokemon)].monsterId;
         return MONSTER_CASTFORM;
     }
 
@@ -1863,7 +1861,7 @@ void ResetMonEntityData(EntityInfo *entInfo, bool8 setStatsToOne)
     }
 
     if (hasForecast) {
-        entInfo->types[0] = gUnknown_80F520C[GetApparentWeather(NULL)].unk0;
+        entInfo->types[0] = gCastformByWeather[GetApparentWeather(NULL)].type;
         entInfo->types[1] = TYPE_NONE;
     }
     else {
diff --git a/src/code_807E5AC.c b/src/code_807E5AC.c
new file mode 100644
index 000000000..a4d3d5627
--- /dev/null
+++ b/src/code_807E5AC.c
@@ -0,0 +1,177 @@
+#include "global.h"
+#include "weather.h"
+#include "code_804267C.h"
+#include "code_803E46C.h"
+#include "dungeon.h"
+#include "dungeon_leader.h"
+#include "dungeon_util.h"
+#include "dungeon_message.h"
+#include "string_format.h"
+
+extern u8 gUnknown_203B40D;
+extern OpenedFile *gUnknown_202ECA0;
+extern void sub_804178C(u32);
+
+void sub_803E874(bool8 r10, s32 r9);
+void GetWeatherName(u8 *dst, u8 weatherId);
+
+void sub_807E7FC(bool8 arg0);
+void sub_807E8F0(Entity *pokemon);
+
+extern const u8 *const gUnknown_80FC5E0;
+
+// Note: gUnknown_202ECA0 file's 2d array is read as 1d array in functions below, be careful!
+void sub_807E698(bool8 arg0)
+{
+    s32 i, j;
+    s32 weatherArrId = GetApparentWeather(NULL) * COLOR_RAMP_COUNT;
+    RGB *fileData = (void *) gUnknown_202ECA0->data;
+    u8 savedByte;
+
+    sub_8042818(GetApparentWeather(NULL), arg0);
+    sub_803E46C(0x25);
+    sub_804178C(1);
+    savedByte = gUnknown_203B40D;
+    gUnknown_203B40D = 1;
+
+    for (i = 0; i < 64; i++) {
+        bool8 r7 = FALSE;
+
+        sub_803E46C(0x25);
+        for (j = 0; j < COLOR_RAMP_COUNT; j++) {
+            if (abs(gDungeon->colorRamp[j].r - fileData[weatherArrId + j].r) < 10) {
+                gDungeon->colorRamp[j].r = fileData[weatherArrId + j].r;
+            }
+            else {
+                r7 = TRUE;
+                if (gDungeon->colorRamp[j].r < fileData[weatherArrId + j].r) {
+                    gDungeon->colorRamp[j].r += 10;
+                }
+                else if (gDungeon->colorRamp[j].r > fileData[weatherArrId + j].r) {
+                    gDungeon->colorRamp[j].r -= 10;
+                }
+            }
+
+            if (abs(gDungeon->colorRamp[j].g - fileData[weatherArrId + j].g) < 10) {
+                gDungeon->colorRamp[j].g = fileData[weatherArrId + j].g;
+            }
+            else {
+                r7 = TRUE;
+                if (gDungeon->colorRamp[j].g < fileData[weatherArrId + j].g) {
+                    gDungeon->colorRamp[j].g += 10;
+                }
+                else if (gDungeon->colorRamp[j].g > fileData[weatherArrId + j].g) {
+                    gDungeon->colorRamp[j].g -= 10;
+                }
+            }
+
+            if (abs(gDungeon->colorRamp[j].b - fileData[weatherArrId + j].b) < 10) {
+                gDungeon->colorRamp[j].b = fileData[weatherArrId + j].b;
+            }
+            else {
+                r7 = TRUE;
+                if (gDungeon->colorRamp[j].b < fileData[weatherArrId + j].b) {
+                    gDungeon->colorRamp[j].b += 10;
+                }
+                else if (gDungeon->colorRamp[j].b > fileData[weatherArrId + j].b) {
+                    gDungeon->colorRamp[j].b -= 10;
+                }
+            }
+        }
+
+        sub_803E874(FALSE, 0);
+        if (!r7)
+            break;
+    }
+
+    gUnknown_203B40D = savedByte;
+    sub_807E7FC(arg0);
+}
+
+void sub_807E7FC(bool8 r0)
+{
+    s32 i;
+
+    Entity *cameraTarget = gDungeon->unk181e8.cameraTarget;
+    if (cameraTarget == NULL) {
+        cameraTarget = GetLeader();
+    }
+
+    if (r0) {
+        if (gDungeon->unk1356C == 0) {
+            GetWeatherName(gFormatBuffer_Monsters[0], GetApparentWeather(NULL));
+            LogMessageByIdWithPopupCheckUser(cameraTarget, gUnknown_80FC5E0); // Weather: {ARG_POKEMON_0}
+        }
+    }
+
+    for (i = 0; i < DUNGEON_MAX_POKEMON; i++) {
+        Entity *pokemon = gDungeon->activePokemon[i];
+        if (EntityExists(pokemon)) {
+            sub_807E8F0(pokemon);
+        }
+    }
+}
+
+void sub_807E88C(void)
+{
+    s32 i;
+    s32 weatherArrId = GetApparentWeather(0) * COLOR_RAMP_COUNT;
+    RGB *fileData = (void *) gUnknown_202ECA0->data;
+
+    for (i = 0; i < COLOR_RAMP_COUNT; i++) {
+        gDungeon->colorRamp[i].r = fileData[weatherArrId + i].r;
+        gDungeon->colorRamp[i].g = fileData[weatherArrId + i].g;
+        gDungeon->colorRamp[i].b = fileData[weatherArrId + i].b;
+    }
+
+    sub_803E874(0, 0);
+}
+
+/*
+void sub_807E8F0(Entity *pokemon)
+{
+    u8 oldTypes[2];
+    u8 uVar4;
+    OpenedFile *sprite;
+    bool8 flag = FALSE;
+
+    if (EntityExists(pokemon)) {
+        EntityInfo *info = GetEntInfo(pokemon);
+        s32 apparentID = info->apparentID;
+        oldTypes[0] = info->types[0];
+        oldTypes[1] = info->types[1];
+        CalcSpeedStage(pokemon);
+        if (HasAbility(pokemon, ABILITY_FORECAST)) {
+            info->types[0] = (gUnknown_80F520C)[GetApparentWeather(pokemon) << 2];
+            info->types[1] = TYPE_NONE;
+        }
+        else {
+                if ((info->protectionStatus != 0xC) && (info->isColorChanged == FALSE)) {
+                info->types[0] = GetPokemonType(info->id, 0);
+                info->types[1] = GetPokemonType(info->id, 1);
+            }
+        }
+        if ((oldTypes[0] != info->types[0]) || (oldTypes[1] != info->types[1])) {
+            flag = TRUE;
+        }
+        if ((u16)(info->id - 0x178U) < 4) {
+            if (HasAbility(pokemon, ABILITY_FORECAST)) {
+                info->apparentID = sub_8069F54(pokemon, info->id);
+            }
+            else {
+                info->apparentID = 0x178;
+            }
+            if (info->apparentID != apparentID) {
+                sprite = sub_80687D0();
+                pokemon->sprite = sprite;
+                uVar4 = sub_806CEBC(pokemon);
+                sub_806CCB4(pokemon,uVar4);
+                flag = TRUE;
+            }
+        }
+        if (flag) {
+            sub_80429D8(pokemon);
+        }
+    }
+}
+*/
diff --git a/src/weather.c b/src/weather.c
index 3293f369f..1a5976f7f 100644
--- a/src/weather.c
+++ b/src/weather.c
@@ -25,8 +25,8 @@ void sub_807E5AC(void)
 {
     u8 weather;
     weather = gDungeon->unk1C574.unk4;
-    if(weather == WEATHER_RANDOM)
-        weather = DungeonRandInt(WEATHER_RANDOM);
+    if(weather == WEATHER_COUNT)
+        weather = DungeonRandInt(WEATHER_COUNT);
     sub_807E5E4(weather);
     TriggerWeatherAbilities();
     sub_807EAA0(0, 1);