On 14/11/2013 09:57, John Hall wrote:
In article ,
Vidcapper writes:
On 13/11/2013 20:29, Colin Youngs wrote:
Wednesday 13th November 2013

UK min. temps on Tuesday night http://tinyurl.com/bas2wpv

Bala, Marham and Northolt -1.1°C, Exeter Airport -1.3°C, Shobdon
and Pembrey Sands -1.4°C, Farnborough -1.6°C, Pershore -1.7°C,
Bournemouth (Hurn) -2.1°C, Benson -3.4°C.


I received confirmation that the minima I now record in my tree-
overhung garden are unrepresentative, since in open areas
around, there was frost in evidence, yet I recorded no lower than
+2C.

On a clear night it's quite possible that there was a ground frost when
the air temperature as measured at the proscribed height above the
ground fell no lower than 2C.


True - but by 'frost in evidence' doesn't necessarily mean only on the
ground...


--

Paul Hyett, Cheltenham