In Baku and Absheron peninsula on September 15, the weather will be mostly dry.

The National Department for Hydrometeorology of the Ministry of Ecology and Natural Resources

North-west wind will be followedwith south-east wind in the afternoon.
The temperature will be +19-22˚C at night, +30-35˚C indaytime in Absheron peninsula, +20-22˚C at night, +32-34˚C in the afternoon in Baku. Air pressure records 760.
Relative humidity will be 75-785% at night 50-55% in the afternoon.

In the regions of Azerbaijan
On September 15, the weather will be mostly dry. 
Mist is predicted in some places in the morning. East wind will blow. 
The temperature will be +18-23˚C at night, +30-35˚C in daytime, +13-18˚C in mountains at night, +22-27˚C in daytime.