Is there a network of people installing such weather stations and sharing their info? I thought a crowd-source weather information like that could be very useful.
There's also the Citizen Weather Observer Program [1]. It's more North America-centric (where the data even gets ingested for use by some weather forecast models, after various data quality checks), but anyone from anywhere in the world is also free to share their weather data.
All Netatmo owners can put their local weather station on an open service. You can find it by searching for Netatmo Weathermap and the data is very dense in populated zones. I was able to fairly accurately pinpoint the location of where rain is/was in the town. I'm surprised Netatmo hasn't leveraged this data better.
The UK Met Office runs WOW (Weather Observations Website) which allows users from all over the world to submit their own observations: https://wow.metoffice.gov.uk/
Weatherunderground hater here. There are a large number of stations (Ambient Weather is a big seller in the US) that hook up neatly and conveniently to only supply data to wunderground.
But then you are 100% reliant upon them for their graphs and app displays, which are slow and often broken, and give you little choice in formatting. For example, the app doesn't display a wind history at all, but the web does. But it won't display on a variety of mobile devices very well.
I know they're free (at the advertising level anyway) but I would love to see some competition with better display options and broader browser / device support.
I currently "tee" my transmissions through another server, but only because I have a model of station (no longer made) that made this trivial. Now you have to intercept the RF which is much more of a pain.
https://www.pwsweather.com/ is another alternative to wunderground. Lately weatherunderground has kind of sucked - it has been down for a while, and rather slow -- and I the deprecation of the old API after IBM bought them was a pain to deal with. Still, their API is public, and the data that weatherstations send to it can be intercepted and used in your own system, for example openhab or home assistant.
The Galaxy S4 had a hygrometer, 'ambient' thermometer, and barometer. Most phones have dropped the thermometer (too sensitive to temp fluctuations to make much sense, surface temps not that useful for weather prediction in urban areas, etc) and the hygrometer (waterproofing), but most have kept the barometer.
It's my long passion to 'activate' all the billions of barometers and use them in weather forecasting. There shouldn't really be much need to manufacture so many weather stations when so much can be done using already deployed hardware (smartphones).
I know IBM is doing assimilation of barometer data into their new models from Weather Underground app installs, and I suspect Apple may finally glance at using their iPhone barometers for weather forecasting now that they bought Dark Sky, but I also don't trust either group to make the results and research public and for the greater societal good - I expect Apple and IBM will mostly use their barometer tech for their own internal, private weather forecast systems.
[1]: https://opensensemap.org