I was checking the weather forecast for my next travel to Rio from AccuWeather.com Their database is handy for previous months’ forecasts. Above you can see the overview for September 2012 for Izmir.  It was 27 degrees Celsius on 21.09.2012. You can check it yourself here: http://www.accuweather.com/en/tr/izmir/318290/month/318290?monyr=9/01/2012#