Weather: Chicago Half Marathon
Typical climate in September (an estimate, not measured race-day data). Use it to plan your race strategy, clothing, and hydration.
Typical climate for the race month — an estimate, not a forecast or a race-day record
19°C
Temperature
Range: 14°C – 24°C
71%
Humidity
Moderate
28%
Rain Chance
Low chance of rain
September
Typical race month
Usually on a Sunday
Conditions
Late September in Chicago is mild: average highs are around 24°C and lows around 14°C, with some rain on about 8 or 9 days of the month.
What to Wear
Light cap or visor
Shield from sun and heat
Sunscreen SPF 30+
19°C means sun exposure risk
Extra hydration plan
Increase fluid intake in heat
Hydration Strategy
Before the Race
Normal hydration. Drink to thirst in the 24 hours before. Avoid over-hydrating.
During the Race
Drink at aid stations every 3-4km. Alternate water and sports drink.
After the Race
Rehydrate within 30 minutes of finishing. A drink with electrolytes and some protein helps recovery.
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