Chicago Weather in August

🇺🇸 United States

26°C

High

20°C

Low

Rain Days

12h

Sunshine

65%

Humidity

North America › 🇺🇸 United States › Chicago

Updated: March 2026

Is August a Good Time to Visit Chicago?

6/10

Good

August is a good time to visit Chicago (6/10). With 12 daily sunshine hours and only 11 rain days, this month delivers genuinely reliable outdoor conditions, ranking it 3rd sunniest of the year in Chicago. Culture-focused travellers and those who prefer lighter crowds will find August a practical choice, with prices running lower than peak June without sacrificing all the good weather. September offers a similar profile at lower hotel rates if dates are flexible. The main practical note: Chicago's popular sites are busiest between 10am and 3pm regardless of season. Arriving at opening time or after 4pm makes a significant difference to the experience. Planning tips: accommodation is generally available without long lead times, and flight prices are typically lower than peak season. Flexible travellers will find the best deals by booking 2-4 weeks ahead. Mid-week arrivals consistently unlock lower hotel rates than weekend check-ins.

vs July:27°C avg high

August weather in Chicago is defined by a daily temperature swing from 20°C at night to 26°C during the afternoon. Humidity averages 65%, and you can count on around 12 sunshine hours each day. That combination makes August warm and lush, though dressing in breathable fabrics keeps things manageable.

26°C

Avg High

20°C

Avg Low

11 days

Rain Days

12h

Sunshine

65%

Humidity

Temperature in Chicago in August

The 6°C day-night temperature range is typical for continental climates: a light jacket in the morning that you shed by midday and need again after sunset. Humidity averages 65%, which is comfortable for most visitors. On warmer days, lighter fabrics help with the mild stickiness in the afternoon. UV index averages 9 this month, classed as high to very high. SPF 30+ sunscreen, a brim hat, and sunglasses are not optional between 10am and 4pm. Wind averages 19 km/h, light enough to be refreshing on warm days but noticeable in open coastal areas or elevated viewpoints. In Fahrenheit: 79°F average high, 68°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).

Temperature in August

Monthly Precipitation (mm)

What to Wear in Chicago in August

Morning20°CBefore the day warms up

Afternoon26°CPeak daytime temperature

Evening23°CAfter sunset cools down

Packing for Chicago in August means dressing for 26°C days and 20°C evenings. A light cotton tee with a casual overshirt works well at 26°C, the overshirt doubles as a layer for air-conditioned venues. Evening temperatures settle at 20°C, a modest 6°C drop that a light cardigan or denim jacket covers. Comfortable walking trainers are the versatile choice for both outdoor sightseeing and indoor venues. A compact foldable umbrella weighs almost nothing and earns its keep across 11 potential rainy days.

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Local tip: Layers are more practical than a single heavy garment in Chicago. The day-to-evening temperature shift rewards packing a versatile mid-layer you can add or remove as conditions change.

Events in Chicago in August

August has no major festivals or public holidays in Chicago, which is one of its practical advantages for independent travellers. Attractions run at lower capacity than during peak event periods, queues are shorter, and accommodation is easier to find without needing to book many months in advance. Local restaurants, markets, and transport operate at a relaxed pace, making this an ideal time for visitors who prefer a more authentic, unhurried experience of everyday city life rather than large crowds drawn in by a single major headline event.

What to Pack for Chicago in August

Based on 26°C average highs and 11 rainy days

Light layers for morning and evening
Breathable T-shirts and comfortable trousers
UV-protective sunglasses
Quick-dry travel towel
Anti-chafe balm for long walking days
Moisture-wicking synthetic fabrics for active days
Compact folding umbrella
Waterproof outer layer or packable rain jacket
Quick-dry clothing that recovers fast after a shower
SPF 30+ sunscreen
Comfortable walking shoes (a second pair lets the first air out overnight)
Universal travel adapter
Small day pack for city exploration
Reusable water bottle

Best Activities in Chicago in August

Explore outdoor markets and street food stallsMid-morning (10am-12pm)At 26°C, the temperature is ideal for extended walking without overheating
Guided walking tour of the historic centreMorning or late afternoonComfortable temperatures allow several hours on foot without fatigue
Visit rooftop viewpoints and observation decksGolden hour (1 hour before sunset)Warm clear evenings provide exceptional visibility for panoramic photography
Day trip to the surrounding countryside or coastFull day (depart by 8am)August is reliably dry enough for rural day trips without weather risk
Afternoon in a world-class museum or galleryAfternoon (2-5pm)Pairs well with outdoor morning activities and provides a mid-day rest from sightseeing
Coffee-house or traditional cafe culture experienceMid-morning or post-lunchA cultural ritual in this region that rewards slow appreciation regardless of weather
Evening live music, theatre, or opera performanceEvening shows typically at 7-9pmConsistent evening temperatures make getting to and from evening venues comfortable
Visit the main botanical garden or city park at seasonal peakYear-round; best light in morningAugust brings distinct seasonal changes to public green spaces worth exploring
Seek out chilled local specialities: cold-brew tea, ice desserts, or chilled seafood at street-level stallsAny time; most atmospheric in evening marketsHot-weather street food culture peaks in August, with vendors setting up specifically for warm evenings

Why is Chicago warm in August?

August in Chicago reflects a mid-latitude climate pattern, with temperatures averaging 26°C by day and 20°C overnight. The city sits at 42 degrees north latitude, where the balance between solar radiation and heat loss drives conditions that are neither extreme nor static. The warm temperatures reflect a stable high-pressure pattern typical of the season, which suppresses cloud formation and concentrates solar energy at the surface. Day-to-night temperature variation of 6°C is moderate and manageable with a single mid-layer. Climate data: Open-Meteo ERA5 (1991–2020).

Sunshine Hours

The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.

UV Index

A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate -- wear sunscreen. UV 6-7: High -- hat and SPF 30+ essential. UV 8-10: Very High -- limit midday exposure. UV 11+: Extreme -- seek shade between 10am-4pm.

Rain Days

A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.

Humidity

Relative humidity as a percentage. Below 40%: Dry -- skin and throat may feel parched. 40-60%: Comfortable -- ideal for most people. 60-80%: Sticky -- light, breathable fabrics recommended. Above 80%: Muggy -- heat feels more intense; quick-dry clothing is essential.

Frequently Asked Questions: Chicago in August

In August, Chicago experiences average highs of 26°C (79°F) and lows of 20°C (68°F). Expect around 11 rainy days and 12 hours of sunshine per day, with humidity averaging 65%. The 6°C gap between daytime and overnight temperatures is worth planning around: light layers work for most visitors during the day, but an overshirt or cardigan handles the cooler evenings. UV index averages 9, so sun protection is advisable on clear days.

Chicago typically sees 11 rainy days in August, with total precipitation of around 95mm. Rain is moderate and manageable. Showers tend to pass quickly, and a light rain layer or foldable umbrella is sufficient protection for most days. For context, the driest month in Chicago typically sees 4-6 fewer rain days than August.

Pack light layers, a light jacket for evenings, comfortable walking shoes, and sunscreen for Chicago in August. Daytime temperatures of 26°C are pleasant, but the evening drop to 20°C means a jacket is essential if you plan to be out after dark. With 11 rainy days, bring a compact umbrella or waterproof jacket for unexpected showers. Comfortable walking shoes are a priority given the amount of ground most visitors cover.

Yes, August is an excellent time to visit Chicago. With 12 daily sunshine hours and only 11 rainy days, conditions are ideal for sightseeing and outdoor activities. Temperatures averaging 26°C during the day are comfortable for long walks and outdoor dining. This is peak travel season, so booking accommodation in advance and arriving at popular attractions early in the morning helps avoid the busiest periods.

The average high temperature in Chicago in August is 26°C (79°F), and the average low is 20°C (68°F). The mean daily temperature is approximately 23°C (73°F). The day-to-night range of 6°C is moderate, meaning a single light jacket covers most situations. These are 30-year climate normals based on the 1991 to 2020 reference period; individual years will vary, particularly in transitional months like spring and autumn.

The best month to visit Chicago is generally July. July offers the most sunshine at 12 hours per day and only 11 rainy days. Average temperatures reach 27°C, making it comfortable for sightseeing, outdoor dining, and exploring the city. If your travel dates are flexible, planning your trip around July gives you the best chance of dry, bright weather.

August is shoulder or low season in Chicago, meaning fewer tourists and generally lower prices than peak months. With 12 sunshine hours and 11 rainy days, the weather is less of a draw for mass tourism. This is an advantage for travellers who prefer a quieter, more relaxed experience with shorter queues and easier accommodation availability.

In August, Chicago suits a range of activities thanks to mild temperatures around 26°C. Mix of indoor and outdoor activities works well given the moderate chance of rain. Top options include exploring historic neighbourhoods, visiting museums and galleries, local food markets, and day trips to surrounding areas. With 12 hours of sunshine, parks and waterfront walks are particularly enjoyable.

August ranks 3rd sunniest of the year in Chicago, with an average 12 daily sunshine hours. The driest months are February, January, and September. July is the hottest month (27°C avg high); January is the coolest (-1°C). From here, temperatures fall 4°C into September. Compared to last month (July: 27°C high, 11 rain days), August is cooler and equally dry. August is among the top three sunniest months to visit Chicago.

Year-Round Climate

Month	High	Low	Rain Days	Sun	Details
January	-1°C	-7°C	9	6h	View
February	1°C	-6°C	7	7h	View
March	5°C	-2°C	10	8h	View
April	11°C	4°C	12	9h	View
May	18°C	11°C	13	11h	View
June	24°C	18°C	12	12h	View
July	27°C	21°C	11	12h	View
August	26°C	20°C	11	12h	View
September	22°C	16°C	9	10h	View
October	16°C	10°C	9	8h	View
November	8°C	3°C	9	6h	View
December	2°C	-3°C	9	5h	View

Other Months in Chicago

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Plan Your Trip to Chicago

Best Time to Visit Chicago

Data Sources for Chicago

Chicago on Wikipedia Open-Meteo Climate API NOAA National Centers UK Met Office WMO GeoNames

Climate normals represent 30-year averages (1991-2020). Individual years may vary.