On Fri, 13 Mar 2015 11:19:09 -0000
"Eskimo Will" wrote:

I generally find the
grass does not get going until the 30cm soil remains consistently
above 7C.

At a talk some 45 years ago, I think it was said that that temperature
was used as the official start of Spring. If no soil temperatures were
available, an approximation of three consecutive days of mean air
temperatures above 10C was used.

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
I wear the cheese. It does not wear me.
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