Seattle Half Marathon

Seattle, WA|Sunday, November 29, 2026|136 days away
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Weather

Climate Avg
TimeTempDew PtHumidityWindConditions
Start32.3 – 41.2°F34° Crisp79 – 96%5 mph NEPartly cloudy
8:00 AM32.4 – 40.9°F34° Crisp78 – 95%5 mph EPartly cloudy
Finish31.6 – 31.6°F31° Crisp97 – 97%4 mph EPartly cloudy

Based on 3-year average for this date. Real forecast available in 120 days.

Elevation Profile

Loading map…

Course Stats

Net Elevation (downhill)
-156 ft
Distance
13.11 mi
Total Gain
+1,129 ft
Total Loss
-1,285 ft
Max Grade
20.1%
Altitude
230 ft

Mile Splits

MileGrade
1-0.9%
2+1.1%
3-0.7%
4-0.7%
5-2.1%
6+2.2%
7-2.8%
8+1.0%
9-0.1%
10-0.3%
11+1.9%
12-1.2%
13-0.8%
14+5.1%

RM Difficulty Index

57/100Challenging
The Seattle Half Marathon profile costs 1:41 vs a flat course at 4:00-marathon pace. Ranked #4 of 16 half marathons see the full rankings.

Seattle Half Marathon Pace Calculator & Race Plan

The Seattle Half starts at the Space Needle, heads south through downtown, then runs north on the I-5 express lanes before crossing to the University of Washington campus. About 500 feet of gain from the rolling terrain.

Late November in Seattle means cool, likely wet conditions. Our model adjusts for the hills and the Pacific Northwest weather.

Seattle Half Marathon FAQ

When is the next Seattle Half Marathon?

The next Seattle Half Marathon is on Sunday, November 29, 2026.

How long is the Seattle Half Marathon?

The Seattle Half Marathon is 13.1 miles (21.097 km), the standard half marathon distance. It runs in Seattle, WA.

How much elevation gain does the Seattle Half Marathon have?

The Seattle Half Marathon has about 1,129 ft (344 m) of climbing and 1,285 ft of descent, with a maximum grade of 20.1%.

Is the Seattle Half Marathon flat, downhill, or hilly?

The Seattle Half Marathon is a net downhill course, dropping 157 ft (48 m) from start to finish, with 1,129 ft of climbing along the way.

How hard is the Seattle Half Marathon?

Runner's Math scores the Seattle Half Marathon 57/100 (Challenging) — #4 of 16 half marathons in our library, ranked by modeled time cost. The profile costs about 1:41 versus a flat course for a runner at 4:00-marathon pace.