Why does my smoke alarm sound when it’s cold outside?
Your smoke alarm may sound when it’s very cold outside, or if a door adjacent to a heated area is opened, like in an entryway. This is due to condensation (water vapor) in the detection chamber.
The sensor is a particle sensing device, when water condenses in the sensor the unit will go into alarm. The operating temperature of a smoke alarm is between 40 and 100 degrees Fahrenheit
(4-38 degrees Celsius). If the unit is in a garage or attic, you should consider replacing it with a heat
alarm which is not affected by condensation.