Snow foam froze

[Dan-]

I was just cleaning my car. I snow foamed it then was shampooing it. When I was rinsing the car i noticed all the snow foam on the drive way was freezing but the temp was +4. Anyway It took me over an hour to rinse it because it really hangs around. It was like the drive and pavement was covered in black ice. Has this happened to anyone else?

 

[JamesBryan]

Yes, many a time.

Think it may be that the ground temp is colder than the air temp.