Speech happening during summer month on Russian river (9)
I believe the answer is:
inaugural
'speech' is the definition.
(inaugural is a kind of speech)
'happening during summer month on russian river' is the wordplay.
'happening during' becomes 'in'.
'summer month' becomes 'aug' (August).
'on' is a charade indicator (letters next to each other).
'russian river' becomes 'ural' (I've seen this in other clues).
'in'+'aug'+'ural'='INAUGURAL'
(Other definitions for inaugural that I've seen before include "President's address" , "Of a speech made on taking office" , "It may be delivered" , "First address" , "Maiden" .)