New York City edges it in September. New York City averages 17–25°C with high crowds; Chicago 16–23°C with moderate crowds.
By Daan · Last reviewed October 2026
New York City and Chicago
The verdict for September
Best weather
+Warm days, cooler evenings and strong city atmosphere make September one of NYC's best months.
–Major events can increase demand around specific dates.
One of the best months for travellers who prioritise weather and atmosphere.
Summer without the crush
+Warm, dry, comfortable days with noticeably thinner crowds and softer rates than midsummer.
–Good hotel rooms still book up fast on nice weekends.
Warm, dry, comfortable days with noticeably thinner crowds and softer rates than midsummer.
Scores and crowd levels are my own judgement; temperatures are monthly averages. Higher scores are better: quieter, cheaper and more pleasant.
Another month