Boulder Boulder

Boulder, CO, USA • May 25, 2026

Race Day Weather

48°

67° high

Light

Dry

Cool start — fast day potential, big temp swing

A cool 48°F at the start line is ideal for fast times — expect to warm up quickly once you're moving. Temps will climb significantly to 67°F by later miles, so expect fading conditions as the race progresses. Light winds shouldn't be a major factor for pacing.

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Pre-raceRace windowPost-race

The Bolder Boulder (styled as BOLDERBoulder and previously BolderBOULDER) is an annual 10-kilometer run in Boulder, Colorado. The most recent race featured over 54,000 runners, walkers, and wheelchair racers, making it the second largest 10k race in the US and the fifth largest road race in the world. It has one of the largest non-marathon prize purses in road racing. Wikipedia

Course Map

FAQ

When is the 2026 Boulder Boulder?

The 2026 Boulder Boulder will be held on Monday May 25, 2026.

Historical Weather

Based on 25 years of data

Avg Temp

66°F

L:50° H:67°

RunScore

Conditions

Rain Freq

12%

3 of 25 yrs

Wind8mph

Dew38°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

Year	Low / High	Rain	Dew Point
2025 Boulder Boulder Partly cloudy throughout the day with rain. 2025	50°/61°	-	51°
2024 Boulder Boulder Clear conditions throughout the day. 2024	55°/74°	-	34°
2023 Boulder Boulder Clear conditions throughout the day. 2023	54°/77°	-	45°
2022 Boulder Boulder Clearing in the afternoon with early morning rain. 2022	50°/62°	-	29°
2021 Boulder Boulder Becoming cloudy in the afternoon with late afternoon rain. 2021	53°/63°	-	48°
2020 Boulder Boulder Clear conditions throughout the day. 2020	52°/77°	-	30°
2019 Boulder Boulder Partly cloudy throughout the day with rain. 2019	42°/56°	-	41°
2018 Boulder Boulder Partly cloudy throughout the day with afternoon rain. 2018	59°/64°	-	51°
2017 Boulder Boulder Becoming cloudy in the afternoon with rain. 2017	50°/67°	-	41°
2016 Boulder Boulder Clear conditions throughout the day with afternoon rain. 2016	52°/77°	-	38°
2015 Boulder Boulder Partly cloudy throughout the day with late afternoon rain. 2015	44°/62°	-	42°
2014 Boulder Boulder Becoming cloudy in the afternoon. 2014	56°/72°	-	43°
2013 Boulder Boulder Clear conditions throughout the day. 2013	55°/80°	-	24°
2012 Boulder Boulder Clear conditions throughout the day. 2012	51°/71°	-	17°
2011 Boulder Boulder Partly cloudy throughout the day. 2011	55°/62°	-	50°
2010 Boulder Boulder Partly cloudy throughout the day. 2010	46°/65°	-	38°
2009 Boulder Boulder Partly cloudy throughout the day with rain. 2009	43°/51°	-	51°
2008 Boulder Boulder Cloudy skies throughout the day with a chance of rain throughout the day. 2008	37°/41°	Light	45°
2006 Boulder Boulder Partly cloudy throughout the day with late afternoon rain. 2006	38°/56°	-	29°
2005 Boulder Boulder Cloudy skies throughout the day with rain. 2005	41°/48°	Light	52°
2004 Boulder Boulder Partly cloudy throughout the day with morning rain or snow. 2004	34°/48°	Light	26°
2003 Boulder Boulder Partly cloudy throughout the day with late afternoon rain. 2003	67°/87°	-	47°
2002 Boulder Boulder Partly cloudy throughout the day. 2002	53°/79°	-	37°
2001 Boulder Boulder Cloudy skies throughout the day with late afternoon rain. 2001	50°/76°	-	45°
2000 Boulder Boulder Partly cloudy throughout the day. 2000	61°/87°	-	47°