Capital extremely tense after cold weather (7)
I believe the answer is:
climate
'weather' is the definition.
(I've seen this before)
'capital extremely tense after cold' is the wordplay.
'capital' becomes 'lima' (capital of Peru).
'extremely' means to remove the middle letters (letters on the extremes of the word are used).
'after' says to put letters next to each other.
'cold' becomes 'C' (eg on taps).
'tense' with its centre taken out is 'te'.
'lima'+'te'='limate'
'limate' after 'c' is 'CLIMATE'.
(Other definitions for climate that I've seen before include "Cite Mal (anag.)" , "Atmosphere" , "Weather etc" , "Mail, etc (anag.)" , "Prevailing weather conditions" .)