Great Bay 5K | Race for a Healthy Estuary
Great Bay 5K | Race for a Healthy Estuary logo

Great Bay 5K | Race for a Healthy Estuary

Stratham, New Hampshire, United States View on map
Sep 30, 2026 – Oct 24, 2026 (America/New_York local time)
Running

About this race

REGISTRATION IS NOW OPEN!!

Race Date: October 24, 2026

The Great Bay 5K is excited to hold its 28th annual race in 2026!  The GB5K is the final race in the popular Seacoast Road Race Series and supports the non-profit Great Bay Stewards. The course passes the shores of Great Bay, and is a fun, fast, scenic, and mostly downhill event.  In 2026, we are pleased to bring back the Great Bay 55K Challenge - run the entire 55 kilometers in one day, or complete the total distance anytime between October 1 - 24. 

Wheelchair racers are welcome and will start at 8:45 a.m., prior to the 9:00 a.m. runner/walker start. No motorized wheelchairs are permitted, and wheelchair racers are responsible for maintaining their own equipment.

Participants in the 5K events will receive a long-sleeve race shirt, and everyone will get a bib with tear strips that you can take to select establishments for free beer or cider. Please keep in mind that you must register by October 1 to get a race shirt. People who register after that may claim a shirt if any remain on race day.

All proceeds from the Great Bay 5K go to the non-profit Great Bay Stewards, which supports conservation, education, community outreach, stewardship, and research of the Great Bay Estuary.

Pick your distance

Running

Great Bay 55K

With this virtual race registration, you'll receive a long-sleeve race shirt (must register by 10/1/26) and a race bib with one coupon for a free beer or cider.

Sep 30, 2026 Ultra 9:00 AM
$35.00
Open

Great Bay 5K

With this in-person race registration, you'll receive a long-sleeve race shirt (must register by 10/1/26) and a race bib with one coupon for a free beer or cider.

Sep 30, 2026 5K 9:00 AM
$40.00
Open

Typical race-day weather

Based on 6 years of Open-Meteo archive data for this event's race dates in Stratham, plus the 3 days either side.

Temp (°C)
Minimum temperature (race-week average) 9.3° / Maximum temperature (race-week average) 17.4°
Feels Like (°C)
Minimum feels like — heat index / wind chill (race-week average) 7.5° / Maximum feels like — heat index / wind chill (race-week average) 17.4°
Peak wind (km/h)
Strongest wind of the day (race-week average)
17.3
Precip (mm)
Precipitation over the day (race-week average)
3.0mm
Humidity
Mean relative humidity (race-week average)
75.6%
Sunrise
Sunrise at the start line on September 30, 2026 (EDT)
Sunset
Sunset at the start line on September 30, 2026 (EDT)
Daylight
Hours between sunrise and sunset on race day
11h 46m

The sun rises at 6:40 AM and sets at 6:27 PM local time (EDT) in Stratham on September 30, 2026 — 11h 46m of daylight.

Course

No course map published yet.

The organizer hasn't released a route for this event, and we don't publish guesses. If you're the organizer, send us a GPX file and we'll draw the profile.

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Results — Great Bay 5K | Race for a Healthy Estuary

2025 edition View Results
2024 edition View Results
2023 edition View Results
2022 edition View Results
2021 edition View Results
2020 edition View Results

Other races near Stratham

Different organizers, within 40 miles, in the next three months

Find upcoming events by distance:

Where this page comes from. Race details were last updated on . We re-check listings regularly and again in the week before race day.

  • Entries, prices, waves and inclusions — the event's official registration page
  • Temperature and humidity — Copernicus ERA5 reanalysis via Open-Meteo (CC BY 4.0)
  • Elevation and terrain relief — Copernicus DEM GLO-90, ESA (CC BY 4.0)
  • Comparisons and counts — Race Discovery calendar, 3 Stratham events

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