Point-to-point along Lake Superior into Duluth. The lake keeps it cool most years and occasionally fogs the whole course in.
By Brett Heimlich, part-time runner.
Plan for about 59°F (15°C) at the 08:00 start, feeling like 58°F (14°C), with 83% humidity and 5 mph wind, warming to roughly 66°F (19°C) by the finish. It rained on 5 of the last 10 race days. Wear: Short Sleeve Tech Shirt, Running Shorts, Running Cap, Waterproof Jacket.
59°F (15°C)
66°F (19°C)
5 of 10 years
50° to 65°F
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Conditions at the 08:00 start on the race's usual date each year (third Saturday of June). Years when the race was cancelled or moved still show that date's weather. Source: Open-Meteo ERA5 archive.
| Year | Start temp | Feels like | Finish | Humidity | Wind | Rain | Sky |
|---|---|---|---|---|---|---|---|
| 2025 | 62°F (17°C) | 65°F | 79°F | 100% | 3 mph | 0.95 in | Overcast |
| 2024 | 55°F (13°C) | 53°F | 64°F | 85% | 5 mph | 0.24 in | Overcast |
| 2023 | 59°F (15°C) | 59°F | 68°F | 80% | 2 mph | – | Clear |
| 2022 | 55°F (13°C) | 50°F | 60°F | 67% | 9 mph | 0.09 in | Mostly clear |
| 2021 | 62°F (17°C) | 60°F | 64°F | 72% | 6 mph | – | Clear |
| 2020 | 60°F (16°C) | 58°F | 65°F | 71% | 5 mph | – | Mostly clear |
| 2019 | 50°F (10°C) | 45°F | 54°F | 81% | 9 mph | – | Clear |
| 2018 | 56°F (13°C) | 55°F | 64°F | 97% | 6 mph | 0.65 in | Drizzle |
| 2017 | 65°F (18°C) | 66°F | 72°F | 77% | 3 mph | 0.28 in | Mostly clear |
| 2016 | 64°F (18°C) | 67°F | 69°F | 97% | 3 mph | – | Overcast |
Coldest start: 50°F (10°C) in 2019. Warmest: 65°F (18°C) in 2017. Wettest: 0.95 in in 2025.
Built from the 10-year average start conditions by the same engine as the live tool. Treat optional items as corral-only layers you can shed.
Short Sleeve Tech Shirt
Breathable running tee
Waterproof Jacket
Breathable rain protection
Running Shorts
Lightweight with built-in brief
Running Cap
Keep rain out of eyes
Trail or Waterproof Shoes
Better grip and water resistance
✓ Worn by the author
Compression tight for 40 to 55°F, works under shorts
$78
✓ Worn by the author
Fast-drying micromesh tee for warm-weather miles
$75
Packable wind shell for cool morning miles
$115
✓ Worn by the author
Thin, ribbed quarter sock that keeps grit out
$36
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Over 2016 to 2025 the start averaged 59°F (15°C) (feels like 58°F (14°C)) with 83% humidity and 5 mph wind, warming to about 66°F (19°C) by the finish. It rained measurably on 5 of those 10 race days. The coldest start was 50°F (10°C) in 2019; the warmest was 65°F (18°C) in 2017.
For a typical 59°F (15°C) start: Short Sleeve Tech Shirt, Running Shorts, Running Cap, Waterproof Jacket. Dress for about 15°F warmer than the start temperature, since the race itself adds that much, and plan to shed anything you only need in the corral.
The Grandma's Marathon is usually held on third Saturday of June. The next expected date is Saturday, June 19, 2027. Confirm on the official site, since dates occasionally move.
The live forecast on this page comes from Open-Meteo and unlocks 16 days before the race. Forecasts inside 7 days are reliable for temperature within a few degrees; rain timing firms up in the last 2 to 3 days. Until then, the 10-year history above is the best planning guide.
Get a what-to-wear call for the live forecast at your exact location, free, no signup.
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