In message , Sacha
writes
It was -3C at 9.30pm and the frost from last night hasn't cleared parts of
the garden all day. Nor has the ice left any of the ponds.

And there was I thinking that it wasn't as cold as all that because
there was no ice on the canal. (Plenty of ice on ponds, and frost on
shaded bits of ground, and for that matter north-facing roofs.)
--
Stewart Robert Hinsley