### Clue: Artist has designed action that's perfect for a British summer? (8)
### Answer: RAINCOAT 
 ### Explanation: Definition: that's perfect for a British summer
 RA(abbrev. for "Royal Academician", an artist who is a member of the Royal Academy of Arts) **plus**(has) **anagram of**(designed) ACTION.
Defn: Something perfect of the British summer weather given its perverseness (indicated by the question mark).