Race-day weather · Wyndo for runners
Boston Marathon weather
April 19, 2027 · Hopkinton, MA · traditional start around 10:00 AM (America/New_York) — 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
280 days to race day
The live race-day forecast unlocks 274 days from now, when April 19, 2027 enters the 7-day forecast window. Until then, no made-up long-range forecast — the history below is what race morning usually looks like.
The 2027 start time hasn't been published yet — the 10:00 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
50°F
median of 20 years
A warm year
56°F
75th percentile start temp
Rain at the start
15%
3 of 20 measured years
Race-morning weather history
2018 ran in ~38F driving rain and headwind (slowest winning times in decades); 2012 hit ~86F heat. 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
50°F
p75 (a warm year): 56°F
Median dew point
34°F
at the start hour
Rain at the start
15%
3 of 20 measured years
Warmest start
71°F
in 2012
| Year | Start temp | Dew point | Wind | Precip (start hr) | Day's high |
|---|---|---|---|---|---|
| 2026 | 44°F | 29°F | 9 mph | dry | 48°F |
| 2025 | 51°F | 20°F | 4 mph | dry | 60°F |
| 2024 | 58°F | 48°F | 3 mph | dry | 70°F |
| 2023 | 52°F | 50°F | 6 mph | dry | 57°F |
| 2022 | 47°F | 24°F | 4 mph | dry | 55°F |
| 2021 | 58°F | 37°F | 2 mph | dry | 63°F |
| 2020 | 47°F | 28°F | 7 mph | dry | 51°F |
| 2019 | 56°F | 55°F | 8 mph | 1.6 mm | 65°F |
| 2018 | 37°F | 36°F | 15 mph | 0.8 mm | 53°F |
| 2017 | 69°F | 47°F | 11 mph | dry | 71°F |
| 2016 | 66°F | 32°F | 4 mph | dry | 70°F |
| 2015 | 44°F | 38°F | 10 mph | dry | 51°F |
| 2014 | 52°F | 24°F | 5 mph | dry | 68°F |
| 2013 | 46°F | 29°F | 2 mph | dry | 56°F |
| 2012 | 71°F | 57°F | 4 mph | dry | 86°F |
| 2011 | 47°F | 24°F | 12 mph | dry | 58°F |
| 2010 | 48°F | 30°F | 10 mph | dry | 58°F |
| 2009 | 46°F | 29°F | 7 mph | dry | 51°F |
| 2008 | 51°F | 39°F | 4 mph | dry | 64°F |
| 2007 | 49°F | 47°F | 10 mph | 0.8 mm | 50°F |
Slot climatology, honestly framed: 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, because what the slot serves up is exactly the question. 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.
Training for this race?
Wyndo can email you when conditions turn good for a run near Hopkinton, MA — and stay quiet when they don't. (A race-week forecast alert keyed to race day is coming next.)
Get an alert when it's a good time for running
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Race facts
- Start line
- Main St (Route 135), Hopkinton Town Common
- Traditional start (not confirmed for 2027)
- 10:00 AM (America/New_York) — 2027 times not yet published; 130th (2026) schedule: wheelchair 09:06/09:09, handcycle/duo 09:30, pro men 09:37, pro women 09:47, para 09:50, Wave 1 10:00, waves through 10:41.
- Field size
- 2026 finishers 29,021
- Registration
- qualifier + charity
Wyndo is not affiliated with or endorsed by the Boston Marathon (officially the "Boston Marathon presented by Bank of America") 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.