That is just strange. It was summer in my game when I tested. I did get smoke then, but only when it rained and only with a chimney present. When I removed the chimneys, the smoke disappeared. And putting them back made the smoke come back. I didn't monitor what the temps were doing though. But if it is seasonal, I would think that you should see it in spring, fall and winter. I did try with the fireplaces lit and unlit but that didn't seem to make any difference. The smoke only showed when it was raining regardless whether the fireplaces were on or off. Like you, I've no idea as to why it is happening. The only thing I can suggest is to keep watching it was you play the lot and see if it changes.
Hope this helps.
Yeah, its so weird. I'm pretty sure the chimneys aren't supposed to smoke unless there's a fireplace on. Oh well, at least its gone for now.
