As mentioned months ago in the official thread, weather will play a bigger part in TLC.
(Incomplete List)
RainQuote:
Aesthetic Changes:
-Rain effect and darker tint
Map Changes:
-Flooding can open access to new areas
-Flooding can close access to old areas
Battle Bonuses:
+5 HP per turn for Frog Suit
+5 FP per turn for FLUDD Suit
-1 FP per turn for Fire Suit
Halves Special for Fire Suit
Halves Speed for Cape and Tanooki Suit
Heat WaveQuote:
Aesthetic Changes:
-Bright Sunlight, orange tint
Map Changes:
(N/A)
Battle Bonuses:
-1 FP per turn unless Feared, Dark, Tanooki, or Fire Suit
-5 FP per turn for FLUDD Suit
-5 HP per turn if Frog Suit
Halves Special for Frog and FLUDD Suit
SnowQuote:
Aesthetic Changes:
-Snow effect, snow-covered chipset (sometimes)
Map Changes:
-Can freeze water in some levels, granting access to new areas
Battle Bonuses:
Halves Speed for Frog and Fire Suit
Halves Speed for Cape Suit
Sand StormQuote:
Aesthetic Changes:
-Sand effect, yellowish tint
Map Changes:
(N/A)
Battle Bonuses:
Halves Speed unless Tanooki
75% Accuracy unless Tanooki
Dark Comet???
I'll update this list later, I have some stuff to do right now...