Weather Sensors (Sub-GHz)
Decode home weather stations
What it does
SimpleLots of homes have a little outdoor thermometer that sends the temperature to a display inside using radio, so you don't have to run a wire through the wall. This app can catch those messages and show the temperature and humidity — even from your neighbours' sensors.
It's a friendly first project: the signals are simple, common, and completely harmless to listen to, and it feels a bit like magic to read a weather station you can't even see.
How it works
SimpleEvery minute or two the sensor sends the same short pattern of blips carrying the temperature and humidity, and repeats it a few times so the display doesn't miss it. The app knows the patterns for popular brands, so it can pick out the numbers from the blips.
How to use it, step by step
Simple- Open the 'Weather' app.
- Choose the 433 MHz band (the most common).
- Wait a minute or two for a reading to arrive.
- See the temperature and humidity appear.
- Try it again in a different room or outside to catch other sensors.
Examples
Decode two different weather stations and compare their temperature readings side by side.
Time how often your sensor transmits — many report every 30–60 seconds like clockwork.
Spot the low-battery flag in the frame before the display even warns you.
Tips & things to try
- 433.92 MHz is the busiest sub-GHz band in Europe — you'll often catch doorbells and remotes here too.
- If nothing decodes, your sensor may use an unlisted protocol — you'll still see the raw pulses on the waterfall.
- Cold outdoor sensors vs warm indoor ones make the temperature difference obvious and satisfying.