Down here in Lousisiana I have used mine in Dec.. We dont have you average mosquitoes. I dont even call them mosquitoes anymore, more like lil vampires... The will bite through gloves and face masks and if you dont have a heavy jacket on they will penetrate your clothes. The thermacell is a must here... Down here in LA there is always something trying to bite you are suck your blood, ie cotton mouths or mosquitoes....