Monthly climate guide
Chicago weather in August
Expect warm weather in Chicago in August: afternoons reach about 25°C (77°F), while nights drop to around 20°C (68°F). Around 95 mm of rain falls over the month (wet), and skies are a mix of sun and cloud. Daytime highs are about the same as July and 3°C warmer than September.
What stands out in August
- Just 130 km apart, but Chicago runs about 2°C cooler than Milwaukee this month.
- Humidity near 76% makes 25°C feel stickier than it sounds.
- Seasonally, August counts as late summer in Chicago.
- There's little difference between day and night (around 5°C).
Avg high
25°C
77°F
Avg low
20°C
68°F
Rainfall
95 mm
wet
Humidity
76%
relative
Sky
46%
cloud · a mix of sun and cloud
Chicago weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 0°C / 31°F | -5°C / 22°F | 48 mm | 86% | 70% |
| February | 0°C / 32°F | -6°C / 22°F | 61 mm | 85% | 71% |
| March | 5°C / 40°F | -1°C / 30°F | 57 mm | 82% | 65% |
| April | 10°C / 49°F | 3°C / 38°F | 108 mm | 81% | 65% |
| May | 15°C / 60°F | 9°C / 49°F | 129 mm | 83% | 65% |
| June | 21°C / 70°F | 15°C / 59°F | 113 mm | 82% | 57% |
| July | 25°C / 77°F | 20°C / 68°F | 93 mm | 79% | 47% |
| August | 25°C / 77°F | 20°C / 68°F | 95 mm | 76% | 46% |
| September | 22°C / 72°F | 17°C / 62°F | 85 mm | 77% | 48% |
| October | 15°C / 60°F | 10°C / 49°F | 107 mm | 78% | 59% |
| November | 8°C / 47°F | 3°C / 37°F | 59 mm | 80% | 63% |
| December | 3°C / 38°F | -1°C / 30°F | 53 mm | 85% | 73% |
What to pack for August
- T-shirts plus a light layer for the evening
- Comfortable trainers or sandals for long walks
- A compact umbrella or packable rain jacket
- Water-resistant shoes
- Quick-dry fabrics — it feels stickier than the temperature suggests
Is August a good time to visit Chicago?
Our Chicago guide recommends: May to June or September to October, avoiding the bitter winter cold and the most humid days of summer.
A river or lake architecture boat tour is one of the best ways to see the skyline that made Chicago famous for its buildings.
Best time to visit Chicago →Other United States cities in August
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Chicago weather in August. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/usa/chicago/august
<a href="https://weathercompare.eu/weather/usa/chicago/august">Chicago weather in August</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/usa/chicago" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="Chicago weather in August"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/usa/chicago/august">Chicago weather in August</a> – WeatherCompare</p>
Chicago in August: quick answers
Is August a good time to visit Chicago?
Yes. August is one of the best months for Chicago, with highs around 25°C and about 95 mm of rain.
How warm is Chicago in August?
Average highs are about 25°C (77°F) and average lows about 20°C (68°F), based on 10 years of daily data.
Does it rain a lot in Chicago in August?
Chicago typically gets around 95 mm of rain in August — wet.
When is the best time to visit Chicago?
May to June or September to October, avoiding the bitter winter cold and the most humid days of summer.
Figures are long-term averages for the area around Chicago (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.