Seafair Triathlon
About this race
Welcome to the Seafair Triathlon!
Seattle's only triathlon will once again take place on the shores of Lake Washington at Seward Park. Offering participants multiple disciplines on a flat, fast and picturesque triathlon course in the shadows of downtown Seattle. This race is a must do for all triathletes in the northwest.
The event offers participants a unique opportunity to participate in a sprint distance triathlon or super sprint distance in an urban setting. Swimming in a protected cove, riding on closed roadways and running through Seward Park, this is the Pacific Northwest's premier triathlon.
Offering a Kids Triathlon as well, there is a distance for everyone in the family at the Seafair Triathlon! Join us in July for the Seafair Triathlon with over 1,800 health enthusiasts taking part in the event.
Pick your distance
Triathlon
Sprint Triathlon
Sprint Distance Triathlon – 0.5 mile swim, 20K bike ride, 5 Kilometer run
Super Sprint Triathlon
Super Sprint Distance Triathlon – 0.25 mile swim, 20K bike ride, 5 Kilometer run
3 Person Sprint Relay
Sprint Distance Relays – Same as the sprint course
2 Person Sprint Relay
Sprint Distance Relays – Same as the sprint course
Kids Triathlon - Long Course
Kids Long Course – 100-yard swim, 2-mile bike ride, 1-mile run
Kids Triathlon - Short Course
Kids Short Course – 50-yard swim, 1-mile bike ride, 0.5 – .75 mile run (swim in water kids can touch in)
Duathlon
Sprint Duathlon
Sprint Duathlon – 20K bike ride, 5 Kilometer Run
Typical race-day weather
Based on 8 years of Open-Meteo archive data for this event's race dates in Seattle, plus the 3 days either side.
The sun rises at 5:31 AM and sets at 8:59 PM local time (PDT) in Seattle on July 19, 2026 — 15h 27m 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.
Reviews
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Other races near Seattle
Different organizers, within 40 miles, in the next three months
Run Scared
2026 Seattle Ghost Marathon, Half & 50K
Green Lake Sole 5K Run
Alaska Airlines Dawg Dash 5K/10K
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, 133 Seattle events
Spotted something wrong? Tell us and we'll fix it.