Brief account describing July weather, perhaps, hopefully heard! (7)
I believe the answer is:
summary
'brief account' is the definition.
(a summary is a brief overview)
'describing july weather perhaps hopefully heard' is the wordplay.
'describing july weather perhaps hopefully' becomes 'summery' (July is part of summer).
'heard' indicates a 'sounds like' (homophone) clue.
'summery' sounds like 'SUMMARY'.
(Other definitions for summary that I've seen before include "Perfunctory" , "Abstract, short version" , "Brief" , "Recapitulation" , "Precis, gist" .)