Weather: Bolder Boulder
Historical weather data for race day in May. Use this to plan your race strategy, clothing, and hydration.
18°C
Temperature
Range: 10°C – 25°C
45%
Humidity
Low — comfortable
15%
Rain Chance
Low chance of rain
May
Typical race month
Usually on a Monday
Conditions
Late May in Boulder offers pleasant spring weather with cool mornings and mild afternoons. Altitude of 5,430 feet can affect sea-level runners during acclimatization.
What to Wear
Singlet or short sleeve
Ideal racing temperatures
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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