Icy weather (5)
I believe the answer is:
sleet
'icy weather' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sleet that I've seen before include "Partly frozen rain" , "Partially frozen rain" , "Partly melted falling 16 across or 18 down" , "Icy rain" , "Snowy rain" .)