So I purchased the Seasons EP yesterday, started new game, set starting season to Fall (when asked), went to Options and set season length to 4 weeks (so I would have time to explore all that each sea...
I think this largely depends on the world you live. When I played in Willow Creek on a 7 day season it rained and thundered a lot. When I made my seasons 14 day seasons it was a lot more balanced. My current save is in Brindleton Bay and I’ve had one day of rain and thunder in Summer.