I'm on racehorse, in winds, whatever the weather? (4,4,2,5)
I believe the answer is:
come rain or shine
'whatever the weather?' is the definition.
(I've seen this in another clue)
'i'm on racehorse in winds' is the wordplay.
'winds' indicates anagramming the letters (the letters wind around).
'im'+'on'+'racehorse'+'in'='imonracehorsein'
'imonracehorsein' is an anagram of 'COME RAIN OR SHINE'.
(Other definitions for come rain or shine that I've seen before include "no matter what the circumstances may be" , "regardless of circumstances" , "Whatever the weather" , "Whatever the circumstances" .)