Runners will face temperatures starting at 50°F, rising to a maximum of 63°F. With light rain expected throughout and a max wind of 4 mph, conditions will be manageable. Runners should consider a throwaway layer or poncho for the pre-race wait and maintain hydration, adjusting pace conservatively as temperatures rise.

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Distance: 13.1mi

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Race Info

The Autumn Run takes place on the third Saturday of September in Buena Vista, Colorado, in the upper Arkansas River Valley below the Collegiate Peaks. The half marathon starts near Cottonwood Lake and finishes at McPhelemy Park. A 10K, 5K, and free kids' fun run share the same race weekend. Source

Website

Race weekend

Saturday, September 19

9:15 AMHalf Marathon (13.1 mi)

9:30 AM10K (6.2 mi)

9:30 AM5K (3.1 mi)

Course Map

FAQ

When is the 2026 Autumn Run?

The 2026 Autumn Run will be held on Saturday September 19, 2026.

Is the Autumn Run a Boston Marathon Qualifier?

No, the Autumn Run is NOT a Boston Marathon qualifier.

What is the time limit for the Autumn Run?

The time limit for the Autumn Run is 2:00 PM hours.

What will the weather be like for the 2026 Autumn Run?

The forecast calls for a high of 68°F and a low of 43°F with a 100% chance of rain.

Historical Weather

Based on 8 years of data

Avg Temp

57°F

L:52° H:62°

RunScore

Conditions

Rain Freq

0 of 8 yrs

Wind5mph

Dew29°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

Year	Low / High	Rain	Dew Point
2025 Autumn Run Partly cloudy throughout the day with afternoon rain. 2025	52°/60°	-	37°
2024 Autumn Run Becoming cloudy in the afternoon with late afternoon rain. 2024	54°/65°	-	28°
2023 Autumn Run Clear conditions throughout the day. 2023	44°/53°	-	36°
2022 Autumn Run Partly cloudy throughout the day. 2022	52°/64°	-	34°
2019 Autumn Run Clear conditions throughout the day. 2019	50°/62°	-	16°
2018 Autumn Run Clear conditions throughout the day. 2018	61°/71°	-	20°
2017 Autumn Run Partly cloudy throughout the day. 2017	52°/60°	-	31°
2016 Autumn Run Clear conditions throughout the day. 2016	48°/59°	-	29°

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