If you mean that every few seconds they emit a “cheep”, rather than the awful racket that suggests your house is on fire (I guess you would have noticed that by now!!), it means the battery is low.
Batteries tend to drop their voltage slightly in the cold, and rise when they get hotter. I would thus expect a battery close to the end of its life to cause the smoke alarm’s warning in colder weather.
I suggest you replace the battery.