Race-day weather · Wyndo for runners
Grandma's Marathon weather
June 19, 2027 · Two Harbors, MN · traditional start around 7:45 AM (America/Chicago) — not yet confirmed for 2027. What the start usually feels like, year by year — and a live start-time read once the race confirms its schedule and race week arrives.
Countdown
332 days to race day
The live race-day forecast unlocks 326 days from now, when June 19, 2027 enters the 7-day forecast window. Until then, live hourly data is not available; the history below shows what race morning usually looks like.
The 2027 start time hasn't been published yet — the 7:45 AM start shown here is carried from a previous edition. We'll switch on the live start-time read when the race posts its schedule.
Typical start temp
54°F
median of 20 years
A warm year
60°F
75th percentile start temp
Rain at the start
15%
3 of 20 measured years
Race-morning weather history
Usually cool along Lake Superior, but 2023 turned hot and humid (upper 70s-80s F) with heavy medical-tent traffic and elevated DNFs. Wyndo tracks what this calendar slot has actually served up at the start hour — temperature, dew point, wind, and rain — including the years when weather canceled or disrupted the race, and reads the live forecast for the start once the race confirms its schedule and race week arrives.
Median start temp
54°F
p75 (a warm year): 60°F
Median dew point
52°F
at the start hour
Rain at the start
15%
3 of 20 measured years
Warmest start
65°F
in 2025
Scroll sideways to see all columns.
| Year | Start temp | Dew point | Wind | Precip (start hr) | Day's high |
|---|---|---|---|---|---|
| 2026 | 53°F | 52°F | 9 mph | dry | 63°F |
| 2025 | 65°F | 63°F | 4 mph | dry | 77°F |
| 2024 | 50°F | 46°F | 5 mph | dry | 63°F |
| 2023 | 51°F | 49°F | 2 mph | dry | 65°F |
| 2022 | 51°F | 44°F | 8 mph | dry | 57°F |
| 2021 | 55°F | 51°F | 5 mph | dry | 62°F |
| 2020 | 54°F | 49°F | 6 mph | dry | 60°F |
| 2019 | 48°F | 44°F | 8 mph | dry | 54°F |
| 2018 | 52°F | 51°F | 6 mph | dry | 67°F |
| 2017 | 55°F | 53°F | 5 mph | dry | 67°F |
| 2016 | 61°F | 60°F | 4 mph | dry | 73°F |
| 2015 | 59°F | 56°F | 9 mph | 0.2 mm | 68°F |
| 2014 | 48°F | 47°F | 6 mph | dry | 60°F |
| 2013 | 49°F | 47°F | 4 mph | 0.8 mm | 63°F |
| 2012 | 62°F | 59°F | 9 mph | dry | 68°F |
| 2011 | 54°F | 52°F | 10 mph | 0.3 mm | 57°F |
| 2010 | 60°F | 55°F | 10 mph | dry | 64°F |
| 2009 | 61°F | 59°F | 8 mph | dry | 79°F |
| 2008 | 56°F | 53°F | 8 mph | dry | 68°F |
| 2007 | 60°F | 59°F | 6 mph | dry | 73°F |
Slot climatology: each row is the weather at this race's usual calendar slot and start hour (ERA5 reanalysis at the start line) — including years when the edition was canceled or moved. A computed slot date is not a claim the race ran that day.
Your heat-adjusted goal for the marathon
The same cited model as the full calculator, pointed at this race: the median start-hour conditions this calendar slot has served up — climatology, not a forecast.
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Race facts
- Start line
- 893 Scenic Drive (Old Hwy 61) at the Sonju Two Harbors lot
- Traditional start (not confirmed for 2027)
- 7:45 AM (America/Chicago) — 2027 schedule not yet posted; per 2026 official schedule — wheelchair/adaptive 7:35, elites 7:40-7:45, open waves 7:45/8:00/8:10. Garry Bjorklund Half runs the same morning; 5K Friday evening.
- Field size
- 2025 marathon finishers 7,555 (second-largest ever); ~18,000 finishers across all weekend races
- Registration
- open (rolling price tiers from Oct 1; sells out)
Wyndo is not affiliated with or endorsed by the Grandma's Marathon (officially the "Grandma's Marathon") or its organizers. Race names are used descriptively to identify the event; schedules and start times belong to the race — always confirm details on the official site. Weather guidance here is informational, never medical advice, and event alert flags on race day belong to the race's own medical team.