A dry summer month to go topless and acclimatise (6)
I believe the answer is:
attune
'acclimatise' is the definition.
(I've seen this before)
'a dry summer month to go topless' is the wordplay.
'a dry' becomes 'att' (I've seen this in other clues).
'summer month' becomes 'june' (I've seen this before).
'to go topless' means to remove the first letter.
'june' with its initial letter taken off is 'une'.
'att'+'une'='ATTUNE'
'and' is the link.
(Other definitions for attune that I've seen before include "Get used to" , "Harmonize or adapt, to matter or idea" , "Harmonise or adapt to idea or music" , "Adjust (to a situation)" , "Harmonise as with musical instrument" .)