What do these sounds mean when it is raining?

Sometimes when its raining in the game, I hear these low tone sounds (watch your ears - the rain is a little loud):

  • Sound 1
  • Sound 2

Do these sounds signify something or are they just background noise? I don't think I hear them every time it is raining which makes me wonder if they are some sort of significance. I also think the same sounds sometimes play when you go to bed for the night.


Solution 1:

These sounds are simply frogs croaking. You can sometimes see frogs fleeing when you cut down weeds and grass, or while it rains.

A frog near the mountain lake during the rain