2027 Ottawa Marathon - May 30 Countdown

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Race Information

Race	2027 Ottawa Marathon - May 30
City	Ottawa
Date	2027-05-30 at 07:00
Field Size	~5,000 runners
Time Limit	7 hours
Cutoff pace	9:57/km
Timezone	America/Toronto
Official Site	Run Ottawa
Registration	Register · 158 CAD

Race Day Weather

Average Temperature	16°C / 61°F
Humidity	78%
Wind	9.5 km/h
Rain Chance	48%
Typical Conditions	Late-May mornings in Ottawa are cool and often damp, typically 10-16C at the 7:00 am gun and climbing toward 18-22C by midday, with a real chance of rain.

What to Prepare: Start in a throwaway layer for the cool corral, then race in singlet and shorts. Pack a rain shell and plan hydration for a warming, humid second half.

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 9.5 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	11.4°C	16°C	21.2°C
Dew point	5.7°C	11.6°C	17.5°C

Wet-day chance: 48% Runnability: 75/100

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

Course Profile

Course Type	Marathon (42.195 km)
Elevation Gain	200m
Terrain	Road
Profile	Flat and fast with only gentle rolling sections; a certified, Boston-qualifying course famed as Canada's quickest.
Boston Qualifier	Yes — Check your BQ time

Prepare for 2027 Ottawa Marathon - May 30

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 ...

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Free Pace Band Generator — Printable Race Day Wristband

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

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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-...

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Elevation Gain/Loss Impact Calculator

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

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Grade Adjusted Pace (GAP) Calculator — Hills & Strava

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

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Marathon Predictor — 5K, 10K & Half Marathon Race Predictor

Free marathon predictor — convert your 5K, 10K, or half marathon time into race-day estimates from R...

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Featured In

Best Marathons for a PR 2026 Easiest Boston Qualifying Marathons 2027 Flattest Marathons 2026 Most Scenic Marathon Courses in the World (2026) Best Marathons in Canada 2026 & 2027

Frequently Asked Questions

When is the 2027 Ottawa Marathon?

The Tamarack Homes Ottawa International Marathon is held on Sunday, May 30, 2027, with a 7:00 am ET gun start from Ottawa City Hall (110 Laurier Ave W). It is the headline event of Tamarack Ottawa Race Weekend, alongside the half marathon, 10K, 5K and 2K.

Is the Ottawa Marathon a Boston qualifier?

Yes. Ottawa runs on a certified, accurately measured road course that is valid for Boston Marathon qualifying times, and it carries a World Athletics Elite Label. Its flat layout makes it one of the best Canadian options for a BQ attempt. Check your target with the Boston qualifying calculator.

How flat and fast is the course?

Ottawa is widely regarded as Canada's fastest marathon. The route stays close to the Rideau Canal and Ottawa River with only gentle rolling sections and a couple of short bridge climbs as it crosses into Gatineau, Quebec. Total elevation change is modest, so it favours even pacing and PR attempts. Map your splits with the pace calculator.

What is the course time limit?

The official limit is 7 hours. Runners must reach the 27 km marker by 11:30 am ET; anyone slower than that pace may be redirected to keep the course on schedule. That works out to roughly a 9:50 per kilometre average, comfortable for most marathoners.

How much does it cost and how do I register?

Registration for the full marathon is open online through Run Ottawa at about CAD $158 (plus HST), with the fee rising as race day approaches. Race Weekend events are popular and the half marathon regularly sells out, so signing up early is recommended.

What does the course pass and where does it finish?

The point-to-point loop starts and finishes at Ottawa City Hall and showcases the capital: Parliament Hill, the Peace Tower, the National War Memorial, the UNESCO-listed Rideau Canal and the Ottawa River, with a stretch across the river into Gatineau, Quebec. Estimate your finish with the finish time calculator.