On Wed, 24 Sep 2003 09:21:45 +0000 (UTC), Franz Heymann wrote:

I don't go by air frost/ground frost. I go by car frost, ie when
you have to scrape it off the windscreens. First one today :-((

That would be air frost.

No, technically it is a ground frost, ie a frost forming on a surface
due to that surafce radiating heat and cooling below freezing.

An air frost is when the temperature of the air in an standard
stephenson screen (ie 1m above mown grass) is = 0C. Ground frosts can
and do form with the air temperature well above 0C.

Look back for that link to the BBC, it explains things very well.

--
Cheers
Dave. pam is missing e-mail