Bernard Burton wrote:
Air min 4.5C here in Wokingham, grass min +0.3C. Just out of interest there
were 13 ground frosts here in September 1986, yet remarkably that year there
was no air frost until 6th December.


In Bracknell in September 1986 we had 15 ground frosts and 7 air frosts.
Four of the air frosts occurred in the first half of the month. As a
caveat, I ought to mention that these figures are based on the figures I
saw in the Met Office entrance hall at the end of the month, and that
they may have been modified since.

Graham