the title is self evident but the implications are not..
please elaborate on what each season entails and for which part of the world
(it can't snow in the jungle during winter)

Snowy in taiga and plains biomes during the winter. During spring there could be some sf crops in wilderness and during autumn pumpkins in wilderness and maybe the resource pack would change the color of the trees during each season.

Cool idea but for this to be implemented you probably need to be very specific about different places on the map