Ask HN: Best indoor/outdoor temperature/humidity sensor?

AcuRite sells a number of different models, from a bare-bones ~$20 model to the flashier $45 "Weather Station". You can find them all at Walmart.

You hang a remote sensor outside. It radios data to the receiver, a portrait-like wall-mounted display. Both indoor and outdoor values are displayed on the receiver, along with time & date.

Our sensor was misplaced and years later we found it again but the alkaline batteries had corroded the internal circuitry. You can buy a replacement sensor for ~$25 and they are compatible with old displays, but the wife had lost interest. So now we rely on TV & WWW.

Temperature monitors don't always display much below freezing, because the accuracy might not be within the optimum range, but a custom firmware will still let you read the raw sensor data.

LCD speed and contrast diminishes at temperatures that low, but if you're reading the temperature wirelessly, that won't matter.

Batteries have even more trouble with cold, but if you replace the CR2032 with a BR2032, it'll work down to -30 C.

Besides batteries, electronics aren't really damaged by cold itself, so if your sensors are getting permanently damaged in the winter, it's probably from condensation. If you seal the sensor, it won't be able to read humidity, but I will still accurately read the temperature, albeit with a little more lag.