How precise do fermentation temps have to be to prevent off flavors

Searched the forum and couldn't find anything on this topic.

How precise, or narrow a range, do you have to keep your temps during fermentation to prevent off flavors?

I use a fishing cooler with ice packs, and always keep it all the ranges of the yeast, but do have a 5-6 degree swing during the course of the fermentation.

Will this cause problems?

You have a fair amount of leeway on the low side, but not much on the high side. I always aim for the low end of the range for the yeast.

Most of the time you'll be fine as long as you're doing something to keep the temperature rise in check. You also don't want it falling rapidly, very far, or the yeast can poop out and stall fermentation. I generally raise my temp a few degrees after the most active fermentation is done, when the gravity is nearly "final" or what I expect it to be. Just monitor it as much as you can, and otherwise RDWHAHB

Oh, and the longer you can let it clean up after itself often gets rid of any slight imperfections you may have picked up, anyway.

Kind of depends on your own taste and what you like. I don't brew lagers, but for ales, a little warm is ok if you don't mind a little fruitiness. But like frazier said, you have more wiggle room on the low end than the high end. I've gone too high before and ended up with a pretty fruity ale that I wasn't happy with. In instances like that I usually dry hop it. The extra hop flavor seems to mask the fruitiness.