RacesReviewed / Race Intelligence

Boulderthon 2026: The Boulder Marathon

Run 5km2026-09-27

Run through America's running capital with the iconic Flatirons and Colorado mountains as your backdrop during the Boulderthon Marathon. This October race captures the heart of Boulder — a city renowned for its legendary running culture, scenic trails, and fitness-focused community. Whether you're chasing a personal best or soaking in the mountain views, Boulderthon delivers an unforgettable marathon experience through one of America's most scenic cities.

RegisterOpen signupboulderthon.orgLocationBoulder, CORace start area

Choose your distance

Run 0.4miRun 10kmRun 13.1miRun 26.2miRun 5km

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Course format

Trail 5k layout

Course geometry is still filling in, but the race format, location, and planning signals already make the day easier to read.

Elevation profile

Mixed terrain profile

Footing and climbing matter here more than one exact elevation number, so plan for effort swings.

Pressure point

Altitude adjustment

Even a modest rise can feel bigger if you are not acclimated, so keep the early effort calmer than sea-level pace.

Weather bias

Usually weather-dragged

Typical starts are around 53F, so even manageable mornings can still get more expensive later.

Free training plan

Build a free Run 5km plan for this race.

Keep race research first. When you want it, open a quick planner that uses the selected distance, the selected race date, and the course itself.

Course Profile

Boulderthon 2026: The Boulder Marathon Run 5km course overview

Summary course view

This course section is built from a lighter course overview so you can understand how the race is likely to run.

Synced course focus

Mid-course

Mile 1.0 · 0 ft · Course intelligence will improve as GPX and logistics data land.

Course trace

This course view focuses on the best route information currently available.

Pressure model

Pressure points highlight where pacing or effort may change during the race.

What comes next

Use the course, weather, logistics, and reviews together to build your race-day plan.

Difficulty Meter

How hard is a 5K?

Planning read
0/100
Course detail
Moderate
Weather detail
Historical + forecast
Race-day detail
Moderate
Weather view
Forecast preview

Weather read

Mostly neutral

Route-aligned wind gives you a quick feel for how the day may race before you dig into the full weather section.

Jump to weather analysis

Weather Analysis

Boulderthon 2026: The Boulder Marathon Run 5km weather outlook

Forecast + history

Weather blends the live forecast with the race's historical weather patterns to help you plan.

Route-aligned wind

0.0 mph

Interpretation

Mostly neutral

NOAA race-window forecast is not available yet, so this shows the current route anchor sample and the fallback pre-race state.

Course bearing 0.0 degAverage wind 7.0 mphDominant direction W

Estimated weather effect

+2.27%

Heuristic read

Major weather drag

Help score

-41

Historical profile

Historically weather-dragged

Based on 6 years of race-weekend weather in the archive.

Avg start temp 52.8FAvg wind 3.3 mphAligned wind N/A

Tailwind years

0%

Headwind years

0%

Helpful weather

0%

Forecasts use current race-area weather, and history looks at past race-weekend conditions to show what runners have typically faced.

Weather history

2024 race-weekend conditions

Race date

Sep 22, 2024

Avg temperature

53.9F

Avg wind

3.3 mph

Aligned wind

N/A

Historical weather pending

+0.63% estimated finish-time effect · 26 hourly observations

Race zone

73F

Areas Of Smoke

7.0 mph · W

City center

73F

Areas Of Smoke

7.0 mph · W

Finish area

73F

Areas Of Smoke

7.0 mph · W

Course Breakdown

Where the 5K shifts

Course rhythm

Active segment

Settle

This segment is a layout-safe placeholder until richer course data arrives.

Avg grade n/aFocused mile 1.0Pacing watchpoint

Race-Day Logistics

Boulderthon 2026: The Boulder Marathon Run 5km race-day logistics

Planning basics

Race weekend

8 recorded years

The basic race structure is in place for planning.

Distance options

9 distances

This page can show the event correctly even when some race-day detail is still light.

Race-day planning

More details coming

Packet pickup, parking, support flow, and reunion details may still be limited.

Course Map

Route shape, city context, and key course moments in one view.

Map + course context

Map overview

This map gives you a race-area view and course orientation even when the full route is not available.

Highlighted point

Mid-course

Course intelligence will improve as GPX and logistics data land.

Mile 1.00 ftStart

What to watch

Use this map to get your bearings before race day and understand the general shape of the course area.

Course coverage

Detailed route geometry and extra overlays may still be limited for this race.

Why it matters

Boulder, CO should still be easy to plan around, even when some course details are lighter than others.

Planning

Use the Run 5km at Boulderthon 2026: The Boulder Marathon as a planning target rather than a qualification race.

Open entry

Entry posture

Open entry

There is no qualification signal in the current event record.

Race framing

Run 5km planning

The page emphasizes course, logistics, and weather rather than qualification standards.

Boulderthon 2026: The Boulder Marathon official site

Race History

Race history overview

Some history available

Past editions tracked

8

Recorded race years

Archive

Current route view

Available

Run 5km

Current

Benchmarks

Growing archive

More historical context will be added here as the archive grows

In progress

Review Radar

Runner signal for Boulderthon 2026: The Boulder Marathon Run 5km

Runner feedback welcome
CourseCourseLogisticsLogisticsCrowd supportCrowd supportAid stationsAid stationsFinish areaFinish areaRecommendRecommend

Course

0/100

Logistics

0/100

Crowd support

0/100

Aid stations

0/100

Finish area

0/100

Recommend

0/100

Your draft saves locally as you answer.

Common questions

FAQ

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Open the race page for route shape, elevation, weather context, and runner review signals.