What is the weather like in September?
Daytime highs up to 25 Celsius, night lows down to 10 Celsius, rain maybe 2-3 mm for month according to 2010 stats.
September is a great month - too warm to snow - not much rain and a light jacket for the evenings.
The first two weeks of September are usually still with summer like conditions. The temperature usually drops at night to the low teens. Late September you will start to feel the change of temperature, but nothing that a sweater can't cure. Kids are back in school so it's a bit more quiet.