ModsJava
Homeostatic Seasons
Performance and realism-driven full-featured seasons mod, dynamically changing biomes and weather as you play.
I don't know my version or loader
Open the Minecraft launcher and look at the profile you play on — it names both, like fabric-loader-1.21.4. The version also shows in the bottom-right corner of the game's main menu.
No loader in the profile name? Then it's plain Minecraft, and these mods won't run — you need Fabric or NeoForge installed first.

Homeostatic Seasons is a free Minecraft Java mod. Compatible with Minecraft 1.21.1, 1.21.11, 1.21.10. Downloaded 15,845 times (via CurseForge). Download it and open it directly in the game.