This is primarily for air quality by default, but you can get temperature, humidity, etc as well. For each station, someone paid for the hardware and is sharing the data gratis.
You’ve just described Ambient Weather. What I find kinda funny about that is they still try to upsell you to get more than 1 year of data retention.
Luckily, they allow you to configure additional arbitrary locations to pump data to. I wrote a little program to drop that data into an InfluxDB database (along with PurpleAir, AirGradient, AirThings, Solar Data, and Iotawatt). The only practical use I’ve found is to look and see “When was the last time we head three days in a row that were so windy?” I suppose I could do fun stuff with Home Assistant too.
https://map.purpleair.com/
This is primarily for air quality by default, but you can get temperature, humidity, etc as well. For each station, someone paid for the hardware and is sharing the data gratis.