Month of heat, third more windy (9)
I believe the answer is:
thermidor
'month of heat' is the definition.
'thermidor' can be an answer for 'month' (Thermidor is an example). I'm not certain of the 'of heat' bit.
'third more windy' is the wordplay.
'windy' indicates an anagram (windy suggests disruption).
'third'+'more'='thirdmore'
'thirdmore' is an anagram of 'THERMIDOR'.
Can you help me to learn more?
(Other definitions for thermidor that I've seen before include "Revolutionary month (of the lobster?)" , "Method of cooking lobster" , "month of revolution" , "month in Paris once?" .)