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Chicago, Illinois

Chicago Triathlon weather

Chicago is usually warm and urban, with Lake Michigan wind and heat as the main checks.

OlympicAugustInland-water swim

Typical race window

August weather in Chicago, Illinois

Monthly climate normal from 2016-2025 archive data.

August
Air temperature

19°C-27°C

Average wind

21 km/h

Peak daily wind

42 km/h

Wet-day chance

38%

A typical day in August averages 3.4 mm of precipitation, with average gusts around 36 km/h. Treat this as planning context, not a live forecast.

Jan

0°C

Feb

3°C

Mar

8°C

Apr

13°C

May

19°C

Jun

25°C

Jul

27°C

Aug

27°C

Sep

24°C

Oct

17°C

Nov

9°C

Dec

3°C

Swim

Lake Michigan can be calm or choppy depending on wind direction and local conditions.

Bike

Urban roads make wind, wet surfaces and visibility relevant for handling.

Run

Heat and humidity can build quickly on the lakefront run.

Live race-day forecast

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This race page stays evergreen. For date, start time and expected segment durations, open the race-day planner with Chicago, Illinois prefilled.

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