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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