All-Out Fallfest Half Marathon

Westminster, CO, USA · September 19, 2026

59°·69° high·Breezy·Dry

Weather

Race Day Weather

59°at start

72° high

Breezy

Dry

Cool start, warming trend ahead

Runners will face a temperature rise from 53°F at the start to 77°F by the finish, with average humidity at 36%. Light winds at 7 mph will vary, featuring headwinds in the early miles and beneficial tailwinds around mile 10. To optimize performance, runners should start conservatively and adjust their pacing for the warmer late race conditions, especially after the notable descent at mile 10.

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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.

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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 is the time limit for the All-Out Fallfest Half Marathon?

The time limit for the All-Out Fallfest Half Marathon is 4 hours.

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

The forecast calls for a high of 74°F and a low of 59°F with a 42% chance of rain.

Historical Weather

Based on 10 years of data

Avg Temp

70°F

L:50° H:70°

RunScore

Conditions

Rain Freq

0 of 10 yrs

Wind4mph

Dew39°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°/72°	-	45°
2024 All-Out Fallfest Half Marathon Clear conditions throughout the day. 2024	55°/74°	-	39°
2023 All-Out Fallfest Half Marathon Clear conditions throughout the day. 2023	46°/65°	-	40°
2022 All-Out Fallfest Half Marathon Partly cloudy throughout the day with afternoon rain. 2022	50°/70°	-	46°
2021 All-Out Fallfest Half Marathon Clear conditions throughout the day. 2021	46°/73°	-	40°
2020 All-Out Fallfest Half Marathon Clear conditions throughout the day. 2020	52°/76°	-	43°
2019 All-Out Fallfest Half Marathon Becoming cloudy in the afternoon. 2019	53°/69°	-	30°
2018 All-Out Fallfest Half Marathon Clear conditions throughout the day. 2018	47°/76°	-	37°
2017 All-Out Fallfest Half Marathon Partly cloudy throughout the day with rain. 2017	47°/52°	-	41°
2015 All-Out Fallfest Half Marathon Clear conditions throughout the day. 2015	49°/70°	-	44°

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