When it rains or is a thunderstorm the game FPS will drop and stay around 2 or 3 FPS. When clear skies and its not raining FPS is higher and is up to 12 to 24 FPS.
MC-68272
Weather lag
Resolved
Invalid
0
Invalid / Works As Intended / Won't Fix
...yes, if it rains, there is more to render, and more rendering means more load on your system.