To get this data into Home assistant we just need a USB dongle that can use the RTL_433 software to decode the signals.

And lucky for us, Benjamin Larsson has a python script that can pull this data from the air and publish it to MQTT.

Turns out most of the these home-based weather stations leverage RF to send data from the sensor back to the base station. I’m a big weather geek and have been working on building a hardware based weather station. While the beauty of Home Assistant’s Choose Your Own Adventure style of Home Automation means you have lots of options when one disappears, it also means we can integrate other hardware that we might already have. Weather Underground, World Wide Lightning Network, and Darksky have all announced they were closing their apis or moving behind a paywall in the last year or two. And while that isn’t bad, it does introduce some risk. Sure now you don’t have to pay extra to bring 60 people with you, but you probably weren’t doing that in the first place.Home Assistant has lots of options for getting weather data, but a lot of them are cloud based. It’s like if your local state park, which used to be free to visit unless you wanted to bring an entire school bus full of people, started charging an entrance fee without warning and that entrance fee was $50/day. I use a couple of them in my own side projects as well, at a total monthly cost to me of less than $5 in the worst case. I have APIs I use at work where we’re making an average of 8 calls per second and it costs us half that for the necessary enterprise tier. But they announced the change with very little lead time, in a market they dominated so there was little competition, and the replacement pricing started at $850/month for the lowest tier. Maybe people were abusing it, maybe the bosses at IBM saw a way to save a few bucks. If they needed to retire their free API tier that’s frustrating enough, but it happens. That’s really the crux of the negative sentiment.

Most people who use WU aren’t contributors, they’re consumers, and now you have to use their website or app rather than pulling the data into your own system. I mean they had a free API to access weather data, which was very useful to home automation users.

Home assistant wunderground