Santa Rosa Half Marathon

Starting at 61°F, heat will be a factor from the gun — go out conservative and stay on top of hydration. Moderate humidity at 68% is worth noting for effort level, especially in later miles.

Race day forecast available in 266 days

5 AM

6 AM

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8 AM

Start

9 AM

10 AM

Finish

11 AM

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1 PM

Cutoff

2 PM

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Distance: 13.1mi

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A mile-by-mile breakdown of where your time goes, weather-adjusted splits, fueling timeline with aid stations, packing checklist, carb tracker, spectator guide, all built around your goal and race-day conditions.

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About the Santa Rosa Half Marathon

The Santa Rosa Half Marathon starts at Old Courthouse Square in downtown Santa Rosa and drops quickly onto the Santa Rosa Creek Trail and Prince Memorial Greenway. Most of the 13.1 miles is paved, tree-lined creekside path with very little elevation change, heading west out of town and returning the same way to the finish downtown. It is a USATF-certified course run on the Sunday of race weekend, and the flat profile makes it one of the faster half marathons in Sonoma County.

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Race weekend

Saturday, August 21

7:00 AM10K (6.2 mi)

9:00 AM5K (3.1 mi)

Sunday, August 22

6:30 AMMarathon (26.2 mi)

7:45 AMHalf Marathon (13.1 mi)

Santa Rosa Half Marathon FAQ

When is the 2027 Santa Rosa Half Marathon?

The 2027 Santa Rosa Half Marathon will be held on Sunday August 22, 2027.

What is the time limit for the Santa Rosa Half Marathon?

The time limit for the Santa Rosa Half Marathon is 5 hours.

What will the weather be like for the 2027 Santa Rosa Half Marathon?

The forecast calls for a high of 81°F and a low of 58°F with a 0% chance of rain. Check our detailed hourly forecast above for the best half marathon race plan.

What is the weather usually like for the Santa Rosa Half Marathon?

Over the 17 years racecast.io has race-day weather for (2009 to 2026), it averaged 54°F at the start and 58°F by a typical finish. It has not rained during race hours in any of those years.

What was the hottest Santa Rosa Half Marathon?

Of the 17 years on record, 2017 was the warmest, reaching 66°F during race hours. The coldest start was 2026, at 50°F.

What was the windiest Santa Rosa Half Marathon?

Of the 17 years on record, 2024 was the windiest, with wind averaging 4 mph during race hours. The calmest was 2013, at 0 mph.

Santa Rosa Half Marathon weather history

Based on 17 years of data

Avg Temp

56°F

L:54° H:58°

RunScore

Conditions

Rain Freq

0 of 17 yrs

Wind2mph

Dew52°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

Year	Low / High	Rain	Dew Point
2026 Santa Rosa Half Marathon Clear conditions throughout the day. 2026	50°/62°	-	52°
2025 Santa Rosa Half Marathon Clearing in the afternoon. 2025	56°/56°	-	54°
2024 Santa Rosa Half Marathon Clear conditions throughout the day. 2024	50°/62°	-	54°
2023 Santa Rosa Half Marathon Clearing in the afternoon. 2023	55°/56°	-	54°
2022 Santa Rosa Half Marathon Clearing in the afternoon. 2022	56°/57°	-	53°
2021 Santa Rosa Half Marathon Partly cloudy throughout the day. 2021	55°/56°	-	53°
2019 Santa Rosa Half Marathon Clearing in the afternoon. 2019	55°/58°	-	56°
2018 Santa Rosa Half Marathon Partly cloudy throughout the day. 2018	53°/53°	-	52°
2017 Santa Rosa Half Marathon Clear conditions throughout the day. 2017	55°/66°	-	53°
2016 Santa Rosa Half Marathon Clearing in the afternoon. 2016	58°/59°	-	36°
2015 Santa Rosa Half Marathon Clearing in the afternoon with afternoon rain. 2015	60°/62°	-	55°
2014 Santa Rosa Half Marathon Clearing in the afternoon. 2014	58°/59°	-	54°
2013 Santa Rosa Half Marathon Partly cloudy throughout the day. 2013	57°/63°	-	56°
2012 Santa Rosa Half Marathon Clearing in the afternoon. 2012	53°/54°	-	50°
2011 Santa Rosa Half Marathon Clearing in the afternoon with late afternoon rain. 2011	51°/52°	-	51°
2010 Santa Rosa Half Marathon Clearing in the afternoon. 2010	51°/53°	-	48°
2009 Santa Rosa Half Marathon Clearing in the afternoon. 2009	52°/54°	-	51°