2026 Mount Desert Island Marathon - Oct 18 Countdown

Q: When is the 2026 Mount Desert Island Marathon and what time does it start?

The 2026 Mount Desert Island Marathon is on Sunday, October 18, 2026, with the full marathon starting at 8:00 a.m. ET in downtown Bar Harbor, Maine. The point-to-point course finishes in Southwest Harbor. A half marathon (starting later in Northeast Harbor) and a team relay run the same morning and share the Southwest Harbor finish.

Q: How hilly is the Mount Desert Island Marathon? How much elevation gain?

It is genuinely hilly — this is not a flat PR course. Total elevation gain is roughly 1,700 feet (about 518 m) over the 26.2 miles. The toughest sections are a 150-foot climb over the ridge by mile 3, constant rolling hills from mile 6 to mile 21, and a brutal final stretch of uphill, a steep descent, and a last climb near mile 25 before the Southwest Harbor finish. Plan a conservative pace and check the climbs with our elevation profile tool.

Q: Is the Mount Desert Island Marathon a Boston qualifier?

Yes — it is a USATF-certified course (certification #ME23002JG) and an official Boston Marathon qualifier. Your finish time counts toward Boston with no downhill adjustment. That said, the hilly terrain makes it a hard place to run a fast time, so it is more of a scenic bucket-list race than a reliable BQ machine. Check your target splits with our Boston qualifying calculator.

Q: What is the time limit for the Mount Desert Island Marathon?

The marathon has a 6.5-hour (6:30) time limit, which works out to roughly a 15-minutes-per-mile average pace. With the hilly course, build in extra time on the climbs and use our pace calculator to set a realistic, even effort rather than even pace.

Q: How much does the Mount Desert Island Marathon cost and how do I register?

The 2026 marathon entry is tiered, starting around $145 in the early window and rising to about $170 closer to race weekend. There is no race-day registration — all runners must sign up in advance. Register through the official site at runmdi.org; the field is small (around 800 marathon finishers in recent years) and can sell out.

Q: Why is the Mount Desert Island Marathon a bucket-list race?

It runs along the rugged Maine coast through Mount Desert Island, home of Acadia National Park, with granite shores, evergreen forest, Atlantic Ocean views and the run around Somes Sound — often described as the only fjord on the U.S. East Coast. Mid-October hits peak fall foliage, and the small, friendly field gives it a destination, off-the-beaten-path feel rather than a big-city-marathon atmosphere.

-- DAYS

-- HRS

-- MIN

-- SEC

Want personality modes & weather integration? Try the full countdown experience

Race Information

Race	2026 Mount Desert Island Marathon - Oct 18
City	Bar Harbor
Date	2026-10-18 at 08:00
Field Size	~811 runners
Time Limit	6 hours 30 min
Cutoff pace	9:15/km
Timezone	America/New_York
Official Site	Mount Desert Island Marathon
Registration	Register · 145 USD

Race Day Weather

Average Temperature	10.2°C / 50°F
Humidity	84%
Wind	16.9 km/h
Rain Chance	38%
Typical Conditions	Crisp, cool mid-October Maine coast morning at peak fall foliage — chilly air with the chance of a coastal breeze off the Atlantic

What to Prepare: Mid-October on Mount Desert Island starts cold. Expect a race-morning low near 45°F / 7°C climbing to a high around 56°F / 13°C, with damp ocean air and a possible breeze along the shore. A throwaway long-sleeve or gloves at the 8:00 a.m. Bar Harbor start that you can shed by mile 3 is smart; the rolling, exposed coastal stretches can feel cooler than the sheltered village miles.

Based on historical averages for race week. Use our Weather Score Calculator and What to Wear Guide for personalized advice.

Wind Impact on Race Day

Wind at 16.9 km/h can affect your marathon pace by 5-15 seconds per kilometer. Headwinds slow you down exponentially — a 20 km/h wind costs more than twice a 10 km/h wind.

Calculate your wind-adjusted pace →

Race-Week Climate

Based on 20 years of race-week weather (2005-2024), MERRA-2 reanalysis

	Cooler	Typical	Warmer
Temperature	6°C	10.3°C	13.8°C
Dew point	1.9°C	7.8°C	12.5°C

Wet-day chance: 38% Runnability: 73/100

Data: NASA POWER (MERRA-2 reanalysis), NASA Langley Research Center

Course Profile

Course Type	Point-to-point
Elevation Gain	518m
Terrain	Road (paved coastal and village roads throughout, rolling and hilly, point-to-point)
Profile	A genuinely hilly point-to-point — not a flat PR course, and the race is honest about that. The route runs 26.2 miles from downtown Bar Harbor to Southwest Harbor along the rugged coast of Mount Desert Island, the home of Acadia National Park, circling Somes Sound (often called the only fjord on the U.S. East Coast). After a slightly downhill opening mile there is a roughly 150-foot climb over the ridge between Champlain and Dorr Mountains by mile 3, then steady rolling hills from about mile 6 to mile 21, and a brutal finish with several miles of uphill, a steep descent, and one last climb toward Southwest Harbor near mile 25. Total ascent is roughly 1,700 feet (about 518 m). The course is USATF-certified (#ME23002JG) and a Boston Marathon qualifier, but the terrain makes it a hard, savor-the-scenery race rather than a BQ machine — runners chasing Boston should weigh the hills with our boston-qualifying tool. Granite shores, evergreen forest, blue Atlantic views and peak autumn color line nearly the whole route.
Boston Qualifier	Yes — Check your BQ time

Prepare for 2026 Mount Desert Island Marathon - Oct 18

Use our free training tools to get race-ready:

Running Pace Calculator — Min/km, Finish Time & Pace Chart

Free running pace calculator for 5K, 10K, half marathon, and marathon. Get min/km or min/mile, your ...

Use Calculator →

Free Pace Band Generator — Printable Race Day Wristband

Free printable pace band for marathon, half marathon, or custom distance. Choose even, negative, or ...

Use Calculator →

Marathon Wake-Up Time Calculator — Race Morning Timeline

7 AM race, wake at 3:45 AM? Enter the gun time; we work backward through meal, gear, bathroom, warm-...

Use Calculator →

Dew Point Running Calculator — Pace Adjustment Chart

Enter temperature and humidity to calculate dew point and its impact on your running pace. 7-zone ch...

Use Calculator →

Elevation Gain/Loss Impact Calculator

How much will hills slow you down? Enter elevation gain, loss, and distance to see adjusted pace, di...

Use Calculator →

Grade Adjusted Pace (GAP) Calculator — Hills & Strava

Convert uphill or downhill running pace to flat-equivalent GAP in one click. Free grade adjusted pac...

Use Calculator →

View all running tools

Featured In

Best Marathon Destination Races for Travel in 2026 Best Fall Marathons in 2026 (Sep-Nov) Most Scenic Marathon Courses in the World (2026) Best US Marathons 2026

Frequently Asked Questions

When is the 2026 Mount Desert Island Marathon and what time does it start?

The 2026 Mount Desert Island Marathon is on Sunday, October 18, 2026, with the full marathon starting at 8:00 a.m. ET in downtown Bar Harbor, Maine. The point-to-point course finishes in Southwest Harbor. A half marathon (starting later in Northeast Harbor) and a team relay run the same morning and share the Southwest Harbor finish.

How hilly is the Mount Desert Island Marathon? How much elevation gain?

It is genuinely hilly — this is not a flat PR course. Total elevation gain is roughly 1,700 feet (about 518 m) over the 26.2 miles. The toughest sections are a 150-foot climb over the ridge by mile 3, constant rolling hills from mile 6 to mile 21, and a brutal final stretch of uphill, a steep descent, and a last climb near mile 25 before the Southwest Harbor finish. Plan a conservative pace and check the climbs with our elevation profile tool.

Is the Mount Desert Island Marathon a Boston qualifier?

Yes — it is a USATF-certified course (certification #ME23002JG) and an official Boston Marathon qualifier. Your finish time counts toward Boston with no downhill adjustment. That said, the hilly terrain makes it a hard place to run a fast time, so it is more of a scenic bucket-list race than a reliable BQ machine. Check your target splits with our Boston qualifying calculator.

What is the time limit for the Mount Desert Island Marathon?

The marathon has a 6.5-hour (6:30) time limit, which works out to roughly a 15-minutes-per-mile average pace. With the hilly course, build in extra time on the climbs and use our pace calculator to set a realistic, even effort rather than even pace.

How much does the Mount Desert Island Marathon cost and how do I register?

The 2026 marathon entry is tiered, starting around $145 in the early window and rising to about $170 closer to race weekend. There is no race-day registration — all runners must sign up in advance. Register through the official site at runmdi.org; the field is small (around 800 marathon finishers in recent years) and can sell out.

Why is the Mount Desert Island Marathon a bucket-list race?

It runs along the rugged Maine coast through Mount Desert Island, home of Acadia National Park, with granite shores, evergreen forest, Atlantic Ocean views and the run around Somes Sound — often described as the only fjord on the U.S. East Coast. Mid-October hits peak fall foliage, and the small, friendly field gives it a destination, off-the-beaten-path feel rather than a big-city-marathon atmosphere.

What should I wear for the Mount Desert Island Marathon?

Dress for a cold coastal-Maine morning. Race-morning lows are around 45°F / 7°C warming to roughly 56°F / 13°C, with damp ocean air and a possible shore breeze. A throwaway long-sleeve or gloves at the 8:00 a.m. start that you can discard by mile 3 works well; the exposed coastal hills can feel cooler than the sheltered village miles.