Chicago in August

In August, Chicago averages 26°C (79°F) during the day and 19°C (66°F) at night, with frequent rain — about 18 days of the month see precipitation (113 mm total).

High season

Conditions are warm and beach-friendly. Expect daily rain or showers, often in heavy bursts.

It's peak hurricane season in Chicago during August. Travel is possible but expect storm risk, possible flight disruption, and generally lower travel insurance coverage.

26°C
Avg high
19°C
Avg low
18
Rain days
113 mm
Rainfall

How August compares to the rest of the year in Chicago

2nd
warmest month of the 12
5th
wettest month of the 12
10%
of yearly rainfall falls in August
13 h 53 min
daylight on the 15th

August is one of the warmest months in Chicago (2nd of 12) and moderately rainy compared to the rest of the year (5th of 12). Daytime temperature runs 12°C above the annual average (14°C). August runs roughly the same as July (26°C) and cools 3°C in September (23°C).

August sunrise & sunset in Chicago

🌅
Sunrise (15th)
5:58 AM
🌇
Sunset (15th)
7:51 PM
Day length
13 h 53 min

Times shown for Chicago local time (America/Chicago), calculated for the 15th of August. They shift by a few minutes day to day across the month.

Photography light in Chicago — August

Golden-hour and blue-hour windows for the 15th of August, in Chicago's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).

🌅 Blue hour (AM)
4:58 AM – 5:38 AM
🌄 Golden hour (AM)
5:38 AM – 6:38 AM
🌇 Golden hour (PM)
7:11 PM – 8:11 PM
🌆 Blue hour (PM)
8:11 PM – 8:51 PM
Milky Way galactic core
Fair
Core only briefly above the horizon — a marginal month even from dark sites near Chicago.

📅 When to book — Chicago in August

Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on August's tier (High season) and Chicago's popularity.

✈ Flights — lead time
3-4 months
Prices are above off-season but not the absolute peak. Tuesday/Wednesday departures are usually cheaper than weekend ones. ⚠ Peak hazard season — book flexible-change tickets and travel insurance with weather-disruption coverage.
🏨 Lodging — lead time
3-5 months
Wide selection still available at this lead time. Premium properties book first; consider 'last-minute deal' availability at 2-week mark if your dates are flexible.

Crowds & pricing — August in Chicago

High season

This is a busy month in Chicago — not the absolute peak, but tourist numbers are clearly elevated. You'll feel it at headline attractions on weekends and in the historic centre, though side streets and lesser-known sights stay manageable. Prices are above off-season but not at their summit. A good week for first-time visitors who want everything open without the worst of the crush.

Why this tier: comfortable tourism weather Northern Hemisphere summer holidays peak hazard season (1 active)

Sun & mosquito risk — August in Chicago

☀️ UV Index (noon, 15th)
11
Extreme
Stay indoors during midday hours; SPF 50+ even briefly outside, UPF clothing, wide-brim hat, sunglasses essential.
🦟 Mosquito risk
●●●●●
Severe
Severe mosquito season with active disease transmission risk. DEET 30%+, picaridin 20%, long sleeves day and night, treated nets, and check CDC/WHO travel advisories before going.

UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.

Chicago in other months

MonthAvg highAvg lowRainfallRain daysSnow days
January 0°C / 31°F -7°C / 19°F 61 mm 17
February 1°C / 33°F -7°C / 19°F 63 mm 13
March 6°C / 43°F -1°C / 30°F 76 mm 16
April 12°C / 54°F 4°C / 39°F 105 mm 18
May 18°C / 65°F 10°C / 50°F 125 mm 18
June 24°C / 76°F 16°C / 61°F 123 mm 18
July 26°C / 79°F 19°C / 66°F 141 mm 18
August 26°C / 79°F 19°C / 66°F 113 mm 18
September 23°C / 73°F 16°C / 61°F 94 mm 15
October 16°C / 60°F 9°C / 48°F 131 mm 18
November 8°C / 47°F 1°C / 34°F 62 mm 13
December 4°C / 38°F -3°C / 27°F 63 mm 12

Other cities with similar August weather

🌍 See the full ranked list of climate twins for Chicago in August →

Frequently asked questions

How hot is Chicago in August?

In August, Chicago averages a high of 26°C (79°F) and a low of 19°C (66°F) — generally warm.

Does it rain a lot in Chicago in August?

August is quite rainy in Chicago, with about 18 rainy days on average.

Is August a good time to visit Chicago?

August is warm but on the rainy side. It suits travelers who are comfortable with warm weather; check the month-by-month ranking to compare it against the rest of the year.

What should I pack for Chicago in August?

Pack light layers for warm days and cooler evenings, plus a compact umbrella or rain jacket. See the full August packing list for Chicago for a complete, climate-based checklist.

Open Chicago on the interactive map

Check the live 10-day forecast and sunrise/sunset.