A rain sensor just tells you if it’s raining or not. A rain gauge will give you cumulative rainfall values. I know there are DIY projects to make HA-compatible gauges but I’d rather have something out of the box, at least in terms of hardware.
I found this on Amazon, and it appears to be be a clone of a more expensive station by Ambient Weather. It looks like it could be made to work with HA as it has a web interface, but I’m not sure if an app is required for setup. The rain gauge also doesn’t seem super accurate, which is frustrating as that’s the only thing I really care about.
I also have an ecowitt weather station, bought a separate GW1000 receiver which feeds into weewx (completely local) and home assistant. You can also add in up to 8 extra temp and humidity sensors so I have some of those in different rooms and the green house.
The rain measurement is a tipping seesaw type so strong winds can sometimes cause inaccurate results
Edit: https://www.ecowitt.com/shop/goodsDetail/16
Has usb connector too
I have the Ecowitt weather station, fully local, has been solid with HA.
I have a weather flow tempest. Expensive and my first one died after a few years but it works well and gives you cumulative rain readings through its native ha integration.
Does it require an internet connection or can it operate locally? Does it need an app/account?
There is both a local and online integration available. Some of the sensors like the weather forecast (which is the most accurate weather forecast I have ever had for my location) are only available from the cloud, others are available locally.
Which market are you in?
I’m in the US.
Im using a Bresser 7 in 1 with this. But I don’t know how accurate the rain gauge is.
I have the weatherman 2 at my house. It is (unfortunately closed source) a more or less complete weather station, rain sensor (a very good one!), rain gauge, temp, humidity, light sensor, optional wind and wind direction. It involves easy soldering, a little tinkering but its works flawlessly since two or three years in my garden. It is a german project ( http://stall.biz/) no clue if he delivers somewhere else or if the instructions are available in germany. 🤔