The month in detail
What to expect in September
Autumn in Chicago is often underrated: 23°C, golden light and declining crowds. An interesting window. Rain risk remains low (25% of days), leaving good room for outdoor activities. A good balance between weather and crowds, even if July (8.7/10) remains theoretically better.
September ranks 4 out of 12 months in Chicago. Compared to August: −3°C daytime, −1.5h of sun per day.
This month's conditions
What it's like in September
UV index
5 · moderate
protect during midday hours
Feels like
comfortable
15°
Daylight
12.3h of daylight
Air quality
good
AQI 34
Compare
Is September the right month?
The best month in Chicago is July (8.7/10), 0.6 pt higher than September.
Book
Plan your trip
Hotels at their lowest outside peak season, highest on comfortable months. Shoulder seasons offer a good price/climate compromise.
Stay
Hotels & rentals · Chicago
Expedia →
Activities
Tours, tickets, experiences
See ↓
Flights
Multi-airline comparator
Kiwi →
🎟️ Activities & tours · Chicago
GetYourGuide selection · free cancellation
Practical info
What you need to know before you go
Three angles: the country (language, currency, safety, budget), the year-round climate, and the specifics of a city break.
Country · USA
🗣️LanguageEnglish
💶CurrencyUS Dollar ($)
🚗DrivingRight-hand
🛡️Safety ⓘVery safe · 1/5
💰Cost of living ⓘExpensive · 4/5
🌡️ Climate
🌍Climate typeTemperate
📈Climate trend ⓘStable
🔥Hottest monthJuly · 27°C
❄️Coolest monthJanuary · 1°C
🌧️Rainiest month ⓘApril · 32%
🏛️ City break
📅Tourist peak seasonJune → August
☔Indoor sights ⓘYear-round
🚇Public transportGood
Explore
Other destinations in September
If September doesn't convince you for this destination, compare with others.
Location
Where is Chicago ?
Global position + regional geographic context.
🌍 World
🔍 Geographic context
USATemperate climate with a 8.7 → 1.1 gap between best and worst month. 10 years of ERA5 data to choose by project.
41.88°N · 87.63°W
Questions
Frequently asked questions
What is the best time to visit Chicago?
July is the best month with 27.0°C highs, 19.0°C lows, 10.3h of sunshine and 31.0% rainy days. The months of July & June offer comparable conditions.
How many hours of sunshine does Chicago get in July?
Chicago averages 10.3 sunshine hours per day in July. It is the sunniest month with a climate score of 8.2/10.
What is the rainiest month in Chicago?
December is the most unfavourable month with December has the lowest climate score of the year and the lowest climate score of the year.
What are the temperatures at night in Chicago in July?
In July, overnight lows reach 19.0°C, while afternoon highs average 27.0°C.
Is Chicago good in winter?
In winter (December-February), Chicago scores 3.0/10 on average — Difficult period — prefer the peak season.. The best month overall remains July with a score of 8.2/10.
When should you avoid Chicago?
December is the most difficult month to visit Chicago, with December has the lowest climate score of the year. Climate conditions are at their lowest of the year during this period.
Do you need sun protection in Chicago in September?
The average UV index reaches 5 in September in Chicago (moderate), with about 12.3h of daylight. Protect during midday hours.