I am planning to make an attempt on Ushba, Khergiani Route in august or september. Anybody who know when will be best? I know the weather is better in september, but I am concerned how cold it might be high in the mountains as it is quite hard rock climbing. Any tip would be greatly appreciated.

Beginning of august is usually OK. September is also statistically somewhat clearer. But it's all very unpredictable, just have enough reserve days...