- Weather
- 49°Ftypical startModelled estimate
- Field size
- ~400 runners
- Course
- Flat
- Elevation
- 150 ft gain · 0 ft net
Event: Full Marathon Slow Racers - Over 6 Hrs 30 Min to finish
PR9Weather9Experience6
Early May · Mountain West · Out-and-Back
Boise River Marathon
Boise, ID · Sunday, May 2, 2027
Event listed as: Marathon
- Best for PR
- Boston Qualifier
Registration opens on the organizer's site
Typical start
49°
Cooler than 46% of U.S. marathons
Modeled historical conditions
Elevation gain
150ft
Flatter than 64% of races
Estimated total climb
Field size
500
Larger than 14% of races
Estimated field
PR potential
9.1/10
Ahead of 63% of races
Almanac model
Percentiles compare this race against all 224 U.S. marathons in the Almanac.
Course profile
150 ft gain · 0 ft net
Flat course, out-and-back.
0510152026.2
Race-day weather
Modeled from location, month and coastal proximity, not verified race history.
6 AM
41°
Start
49°
Midday
60°
ExcellentGoodWarmHeat risk
Typical start sits at 49°F, excellent marathon conditions.
Typical dew point 37°F, 16% chance of precipitation, wind around 7 mph. All modeled.
The bottom line
A quietly fast race that does not ask for much beyond honest pacing.
Boise River Marathon is a strong choice for a PR attempt, and Boise offers very little meaningful elevation. The tradeoff is atmosphere: expect long quiet stretches and few spectators.
Why runners choose this race
A out-and-back course around Boise, ID, with very little meaningful elevation change.
The case for it
- PR attempts
- Boston qualification
- Runners who want a low-key start
The tradeoffs
- You want crowds and on-course energy
Course and logistics
- Course type
- Out-and-Back
- Surface
- Road
- Profile
- Flat
- Total gain
- 150 ft(estimated)
- Total loss
- 150 ft(estimated)
- Net elevation
- 0 ft(estimated)
- Field size
- ~500 runners(estimated)
- Crowd support
- Quiet, low-key
- Entry
- Easy
- Entry fee
- $60(most recent listed price)
- Day of week
- Sunday
- Start / finish
- Start and finish in the same area
Race details
- Typical timing
- Early May
- Next confirmed date
- Sunday, May 2, 2027
- Registration
- Open now
- Region
- Mountain West
- Editorial tier
- Recommended
- Data last reviewed
- 2026-08-26
- Best for PR
- Boston Qualifier
- Out-and-back
- Flat course
- Easy entry
Similar races
Races with a comparable profile.
- Weather
- 45°Ftypical startModelled estimate
- Field size
- ~1,000 runners
- Course
- Flat
- Elevation
- 200 ft gain
Flat course along Boise River Greenbelt
PR9Weather9Experience7
- Weather
- 50°Ftypical startModelled estimate
- Field size
- ~600 runners
- Course
- Flat
- Elevation
- 50 ft gain · 0 ft net
Event listed as: Marathon
PR9Weather9Experience6