Short day in warmer African country (5)
I believe the answer is:
sudan
'african country' is the definition.
(country in Africa)
'short day in warmer' is the wordplay.
'short' means to remove the last letter.
'in' is an insertion indicator.
'warmer' becomes 'sun' (I've seen this in another clue).
'day' with its last letter taken off is 'da'.
'da' inserted within 'sun' is 'SUDAN'.
(Other definitions for sudan that I've seen before include "Recently-split country" , "Sun ad for the African state" , "African nation" , "Country divided by the Nile" , "Us and the African state" .)