An ideal climate brings out the best in sporting performance. There are few things in life so predictable as the excellence of an Istanbul summer. July is the perfect month. The average temperature between July 16 and August 1 is 24 C (75 F) with humidity under 70 %. A gentle breeze off the Sea of Marmara means that the climate is always comfortable. chance of rain is minimal and the night time is a pleasant 16 C. All providing for nearly the best conditions paving the way for new world records.