All-Out Fallfest Half Marathon

Westminster, CO, USA · September 19, 2026

57°·79° high·Light·Dry

Weather

Race Day Weather

57°at start

82° high

Light

Dry

Cool start, warming rapidly

Runners will face a temperature rise from 53°F at the start to a warm 81°F by the finish. Winds will be light at 6 mph from the S, with gusts up to 16 mph. Given the heat, runners should consider adjusting their pace and staying hydrated, especially as temperatures climb throughout the race.

Race day forecast available in 70 days

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Distance: 13.1mi

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Race Info

The All-Out Fall Fest Half Marathon in Westminster, Colorado, offers runners a scenic journey along the Big Dry Creek Trail, leading to the picturesque Standley Lake Regional Park. Participants enjoy a mix of paved and gravel paths, with breathtaking views of the Flatirons and a notable stretch near the dam. The event embraces 80s nostalgia, adding a fun and energetic vibe to the race experience.

Website

Course Map

FAQ

When is the 2026 All-Out Fallfest Half Marathon?

The 2026 All-Out Fallfest Half Marathon will be held on Saturday September 19, 2026.

What will the weather be like for the 2026 All-Out Fallfest Half Marathon?

The forecast calls for a high of 80°F and a low of 51°F with a 4% chance of rain.

Historical Weather

Based on 9 years of data

Avg Temp

78°F

L:54° H:78°

RunScore

Conditions

Rain Freq

11%

1 of 9 yrs

Wind5mph

Dew34°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

Year	Low / High	Rain	Dew Point
2025 All-Out Fallfest Half Marathon Clear conditions throughout the day with rain. 2025	55°/74°	-	45°
2024 All-Out Fallfest Half Marathon Clear conditions throughout the day. 2024	59°/87°	-	38°
2022 All-Out Fallfest Half Marathon Partly cloudy throughout the day with afternoon rain. 2022	55°/76°	-	45°
2021 All-Out Fallfest Half Marathon Clear conditions throughout the day. 2021	51°/88°	-	38°
2020 All-Out Fallfest Half Marathon Clear conditions throughout the day. 2020	58°/83°	-	39°
2019 All-Out Fallfest Half Marathon Becoming cloudy in the afternoon. 2019	56°/75°	-	29°
2018 All-Out Fallfest Half Marathon Clear conditions throughout the day. 2018	53°/85°	-	31°
2017 All-Out Fallfest Half Marathon Partly cloudy throughout the day with rain. 2017	48°/52°	Light	42°
2015 All-Out Fallfest Half Marathon Clear conditions throughout the day. 2015	52°/81°	-	44°

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