Frost sensor

Is there a sensor that can detect frost?

I want HA to notify me if my car needs scraped in the morning. Currently I check if the temperature drops to below 42F overnight. I get about a 50% success rate.

I think you’d have to factor in dew point and wind speed. Even so I don’t think you’d approach 100%.

That’s why I’d love a sensor that can tell me if it’s covered in frost.

Did You find such a sensor?

Nope, nothing found. Thought about making my own.