Historical Race Day Weather for the Boulderthon - Boulder Marathon

September 27, 2026

Race day snapshot

Partially cloudy

Start Line Conditions

Start Temp 65°F 18°C

Start Humidity 40% Humidity

Wind W 3 mph Wind

Race day high 77°F 25°C

Race day low 58°F 14°C

PR Score 92.04 Normal score 92.68

Course Score 92.68 Course-only Score

Course-adjusted pacing

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September 28, 2025

Race day snapshot

Clear

Start Line Conditions

Start Temp 59°F 15°C

Start Humidity 59% Humidity

Wind No Wind Wind

Race day high 77°F 25°C

Race day low 51°F 11°C

PR Score 91.83 Normal score 92.68

Course Score 92.57 Course-only Score

September 29, 2024

Race day snapshot

Clear

Start Line Conditions

Start Temp 64°F 18°C

Start Humidity 34% Humidity

Wind SSE 0 mph Wind

Race day high 85°F 29°C

Race day low 55°F 13°C

PR Score 91.00 Normal score 92.68

Course Score 91.81 Course-only Score

October 8, 2023

Race day snapshot

Clear

Start Line Conditions

Start Temp 56°F 13°C

Start Humidity 32% Humidity

Wind W 3 mph Wind

Race day high 72°F 22°C

Race day low 45°F 7°C

PR Score 91.81 Normal score 92.68

Course Score 91.81 Course-only Score