2026 Sioux Falls Marathon - Sep 20 Countdown

Q: How do you register for the Sioux Falls Marathon?

Registration is open and first-come &mdash; there is no lottery. Sign up through the official RunSignup page; the full marathon is $88 at the early rate, rising to $95 after the price-increase deadline of July 5, 2026 (11:59 p.m. CDT). Spots are limited and the field is small (404 full finishers in 2025), so register early.

Q: Is the Sioux Falls Marathon a Boston qualifier?

Yes. The course is USATF certified and recognized as a Boston Qualifying race. You do not need a qualifying time to enter &mdash; entry is open to all &mdash; but a qualifying finish here counts toward Boston. The 2025 BQ rate was 6.7%, and it reached 10.1% in 2023.

Q: How hard is the Sioux Falls Marathon course?

It is fast but not pancake-flat. The first half has gently rolling hills, with the two biggest climbs between miles 2-3 (Terrace Park to downtown) and miles 9-13 (Pasley Park to Lewis Park). Total elevation gain is only about 178 m (586 ft). The back half along the river is much gentler, though runners describe the greenway as a subtle false-flat rather than dead flat &mdash; still, the modest total climb is why it carries a high PR rating (PR Score 98.17).

Q: What is the time limit for the Sioux Falls Marathon?

The cutoff is 6 hours 30 minutes, which works out to roughly a 14:53 per mile (9:15 per km) pace. The race starts at 7:00 a.m. CDT from the parking lot east of Howard Wood Field and finishes on the track inside the stadium.

Q: What is the weather like for the September race?

Expect a cool, crisp prairie morning. Late September in Sioux Falls starts near 51&deg;F (11&deg;C) at the 7:00 a.m. gun and warms to about 73&deg;F (23&deg;C) by midday, with comfortable humidity and roughly a 24% chance of a wet day. Open-prairie wind is the main variable &mdash; dress for cold at the start and shed layers.

Q: Where does the course go and what will I see?

The route loops through downtown Sioux Falls, Terrace Park and the city's river parks, then runs long stretches along the Big Sioux River greenway. A highlight near the city is Falls Park, where the river drops over pink Sioux quartzite ledges. The finish is on the track at Howard Wood Field.

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Race Information

Race	2026 Sioux Falls Marathon - Sep 20
City	Sioux Falls
Date	2026-09-20 at 07:00
Field Size	~404 runners
Time Limit	6 hours 30 min
Cutoff pace	9:15/km
Timezone	America/Chicago
Official Site	Sioux Falls Sports Authority
Registration	Register · 88 USD

Race Day Weather

Average Temperature	17.7°C / 64°F
Humidity	64%
Wind	26.5 km/h
Rain Chance	28%
Typical Conditions	Cool, crisp prairie autumn morning with comfortable low humidity

What to Prepare: The 7:00 a.m. start is genuinely cold in late September (around 51°F / 11°C at the gun), warming toward 73°F / 23°C by midday. Wear a throwaway long-sleeve for the corral, and pack arm sleeves you can shed. Open prairie wind can gust to 17 km/h, so check the forecast direction before the river-path stretch.

Based on historical averages for race week. Use our Weather Score Calculator and What to Wear Guide for personalized advice.

Wind Impact on Race Day

Wind at 26.5 km/h can affect your marathon pace by 5-15 seconds per kilometer. Headwinds slow you down exponentially — a 20 km/h wind costs more than twice a 10 km/h wind.

Calculate your wind-adjusted pace →

Race-Week Climate

Based on 20 years of race-week weather (2005-2024), MERRA-2 reanalysis

	Cooler	Typical	Warmer
Temperature	12.3°C	17.9°C	22.7°C
Dew point	3.1°C	10.3°C	16.9°C

Wet-day chance: 28% Runnability: 73/100

Data: NASA POWER (MERRA-2 reanalysis), NASA Langley Research Center

Course Profile

Course Type	Loop (single)
Elevation Gain	178m
Terrain	Road and paved riverside trail
Profile	A fast, PR-friendly Boston qualifier rather than a pancake-flat one. The first half rolls through Terrace Park, downtown and the river parks with the two notable climbs around miles 2-3 and 9-13; the back half along the Big Sioux River greenway is far gentler, though runners report it is a subtle false-flat rather than dead flat. Total climbing is only about +178 m (586 ft), which is why it carries a high PR rating. USATF certified, no qualifying time required to enter.
Boston Qualifier	Yes — Check your BQ time

Prepare for 2026 Sioux Falls Marathon - Sep 20

Use our free training tools to get race-ready:

Running Pace Calculator — Min/km, Finish Time & Pace Chart

Free running pace calculator for 5K, 10K, half marathon, and marathon. Get min/km or min/mile, your ...

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Free Pace Band Generator — Printable Race Day Wristband

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Marathon Wake-Up Time Calculator — Race Morning Timeline

7 AM race, wake at 3:45 AM? Enter the gun time; we work backward through meal, gear, bathroom, warm-...

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Wind Effect on Running — How Much Does Wind Slow You?

How much does a headwind actually slow you down? This free calculator turns wind speed and direction...

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Elevation Gain/Loss Impact Calculator

How much will hills slow you down? Enter elevation gain, loss, and distance to see adjusted pace, di...

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Grade Adjusted Pace (GAP) Calculator — Hills & Strava

Convert uphill or downhill running pace to flat-equivalent GAP in one click. Free grade adjusted pac...

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Frequently Asked Questions

How do you register for the Sioux Falls Marathon?

Registration is open and first-come — there is no lottery. Sign up through the official RunSignup page; the full marathon is $88 at the early rate, rising to $95 after the price-increase deadline of July 5, 2026 (11:59 p.m. CDT). Spots are limited and the field is small (404 full finishers in 2025), so register early.

Is the Sioux Falls Marathon a Boston qualifier?

Yes. The course is USATF certified and recognized as a Boston Qualifying race. You do not need a qualifying time to enter — entry is open to all — but a qualifying finish here counts toward Boston. The 2025 BQ rate was 6.7%, and it reached 10.1% in 2023.

How hard is the Sioux Falls Marathon course?

It is fast but not pancake-flat. The first half has gently rolling hills, with the two biggest climbs between miles 2-3 (Terrace Park to downtown) and miles 9-13 (Pasley Park to Lewis Park). Total elevation gain is only about 178 m (586 ft). The back half along the river is much gentler, though runners describe the greenway as a subtle false-flat rather than dead flat — still, the modest total climb is why it carries a high PR rating (PR Score 98.17).

What is the time limit for the Sioux Falls Marathon?

The cutoff is 6 hours 30 minutes, which works out to roughly a 14:53 per mile (9:15 per km) pace. The race starts at 7:00 a.m. CDT from the parking lot east of Howard Wood Field and finishes on the track inside the stadium.

What is the weather like for the September race?

Expect a cool, crisp prairie morning. Late September in Sioux Falls starts near 51°F (11°C) at the 7:00 a.m. gun and warms to about 73°F (23°C) by midday, with comfortable humidity and roughly a 24% chance of a wet day. Open-prairie wind is the main variable — dress for cold at the start and shed layers.

Where does the course go and what will I see?

The route loops through downtown Sioux Falls, Terrace Park and the city's river parks, then runs long stretches along the Big Sioux River greenway. A highlight near the city is Falls Park, where the river drops over pink Sioux quartzite ledges. The finish is on the track at Howard Wood Field.

When are results posted?

Chip-timed results are posted the same day on the timing partner's site and the official race page, and they feed national databases such as MarathonGuide and FindMyMarathon. The 2025 field of 404 full-marathon finishers averaged 4:25:59.