The 2026 St. Lawrence Marathon has concluded.
St. Lawrence Marathon
Race complete
Cornwall, ON, Canada · April 25, 2026
Race Day Weather
42°at start
57° high
Windy
Dry
Cool start, steady climb
Runners will face a temperature rise from 38°F to 55°F, with a strong wind from the east-northeast at 19 mph. The average humidity is 42% with a dew point of 25°F, providing a dry atmosphere. Given the wind and temperature trend, runners should plan for a steady pace while staying warm early on.
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FAQ
When is the 2026 St. Lawrence Marathon?
The 2026 St. Lawrence Marathon will be held on Saturday April 25, 2026.
Is the St. Lawrence Marathon a Boston Marathon Qualifier?
Yes, the St. Lawrence Marathon is an official Boston Marathon qualifier.
What will the weather be like for the 2026 St. Lawrence Marathon?
The forecast calls for a high of 57°F and a low of 34°F with a 0% chance of rain.
Historical Weather
Based on 4 years of data
Avg Temp
52°F
L:45° H:54°
RunScore
Conditions
Rain Freq
75%
3 of 4 yrs
Wind12mph
Dew40°F
Temperature History
Range of temperatures during race hours for each year.
Detailed History
| Year | Conditions | Low / High | Rain | Dew Point | Score |
|---|---|---|---|---|---|
2025 |  | 46°/50° | Light | 46° | |
2024 | | 46°/71° | - | 30° | |
2023 |  | 47°/55° | Light | 41° | |
2019 | | 39°/42° | Light | 34° |
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