It is -4°F here batteries in the outside digital thermometer are not working. Receiver inside the house show batteries out side are dead. I replaced outside batteries with warm batteries I have in the house now thermometer works again but for how long?
Duracell AAA batteries are not completely dead 2 in series are low enough they don't work in this outside thermometer. I bought new batteries about 4 months ago, batteries usually last longer than a year. I never keep track of the date they might last longer.
It has warmed up from -2° to 9°F thermometer has come on again all by itself. So 11° warmer is enough for battery to work again.
You could use Energizer Ultimate Lithium batteries. I use them in my outdoor weather station.
They are rated for extreme temperatures \( -40 ^{\circ} F - 140^{\circ} F \). They cost a little more than regular batteries and you can find them at Lowes or Home Depot