Fire appears in the overworld even when there is no rain

Problem: For some strange reason, fire randomly spawns in the overworld as if another player lighted the ground with flint and steel. I found this issue in a survival world with no other players in the world or around me.

What should happen: Fire should only spawn in the overworld when lava pools make contact with trees and naturally in the Nether.

How to reproduce: N/A

 

 

Additional notes: Thunder didn't occur at the time of these pictures, and I swear I did not light the ground with flint and steel to make these fires.