When I was in Prague in NOVEMBER, it was under never over about 1
degree,
and mostly was under freezing for the whole weekend..

It also snowed all weekend, not hard but mostly consistant light snow
with
some moderate falls.. and to my surprise, even after 2 days of snow,
virtually none of it had settled - I couldn't believe it.. this was
around
the time that some parts of the UK got a dusting. In fact, on the
train to
Stansted from London there was snow lying. I very much doubt that
more snow
fell here overnight than did in Prague the whole weekend, but like I
said..
no accumulation..

The key word here may be "November". It is now LATE February, and the
sun is, now, MUCH higher in the sky.

Were you in Prague in early, mid, or late November?

Frosts are also MUCH more common in spring than in autumn, due to the
diurnal equinox, but also due to March being the coldest month up in
the Arctic.

D.