Ok, thanks for the replies… Actually I have a custom made rain sensor with a Shelly flood and a pcb. It works, but suffer a lot of fog and humidity in general, so was wondering if I can find something different to use 
exactly why I’m in this thread. I have motorised outdoor blinds on our deck that I’ve got set to close when it rains. At the moment it’s triggered by my weather station but it can take 10 minutes of decent rain before it registers. Looking for something off the shelf closer to immediate. Just a true/false state is enough!