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Boston, Massachusetts10K Usually the fourth Sunday of June

B.A.A. 10K Weather & What to Wear

Boston Common out along Commonwealth Avenue and back, a fast summer 10K. Late-June mornings can be pleasant or already in the 80s and humid.

The quick answer

Plan for about 73°F (23°C) at the 08:00 start, feeling like 75°F (24°C), with 70% humidity and 7 mph wind, warming to roughly 77°F (25°C) by the finish. It rained on 4 of the last 10 race days. Wear: Singlet or Tank, Running Shorts, Running Cap, Waterproof Jacket, Sunscreen.

Feels like 75°F (24°C) at the start · finish 77°F (25°C) · rain 4 of 10 · start air from 66°F (19°C) to 81°F (27°C)

Race-day weather, 2016 to 2025

Conditions at the 08:00 start on the race's usual date each year (usually the fourth Sunday of June). Years when the race was cancelled or moved still show that date's weather. Source: Open-Meteo ERA5 archive.

No time in mind?
← PR band2025202420232022warmest2021202020192018coldest2017201660°F70°F80°F90°F

Bar: air temperature from start to finish · dot: feels-like effective temperature · ≫ windy (15+ mph) · rain · shaded: PR band 40–50°F

See the numbers
YearStart tempFeels likeFinishHumidityWindRainSky
202575°F (24°C)77°F78°F75%10 mph–Overcast
202466°F (19°C)70°F71°F97%5 mph0.09 inRain
202375°F (24°C)80°F77°F82%5 mph0.09 inOvercast
202281°F (27°C)85°F86°F55%3 mph–Clear
202177°F (25°C)79°F80°F80%14 mph–Overcast
202075°F (24°C)79°F79°F69%4 mph0.22 inMostly clear
201971°F (22°C)68°F74°F56%11 mph–Clear
201867°F (19°C)67°F71°F77%6 mph0.40 inMostly clear
201773°F (23°C)73°F76°F59%6 mph–Clear
201672°F (22°C)71°F77°F46%3 mph–Mostly clear

Coldest start: 66°F (19°C) in 2024. Warmest: 81°F (27°C) in 2022. Wettest: 0.40 in in 2018.

How we estimate this

The time estimates apply published temperature–performance curves to this race's ten-year weather history. Performance peaks at an effective race temperature of roughly 40 to 50°F and degrades faster the warmer it gets and the slower you run (Ely et al., 2007; El Helou et al., 2012). Wind adds a cost that grows with the square of the wind speed (Pugh, 1971), split into head and tail components on point-to-point courses. Shorter races are penalised less. This is a model, not a prediction; your training and the course matter more.

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What to wear for a typical B.A.A. 10K

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.

Upper body

  • essential

    Singlet or Tank

    Maximum breathability for hot conditions

  • essential

    Waterproof Jacket

    Breathable rain protection

Lower body

  • essential

    Running Shorts

    Lightweight with built-in brief

Accessories

  • essential

    Running Cap

    Keep rain out of eyes

  • recommended

    Sunglasses

    UV protection

  • essential

    Sunscreen

    SPF 30+ water-resistant

Footwear

  • recommended

    Trail or Waterproof Shoes

    Better grip and water resistance

Race-day tips for the B.A.A. 10K

  • •Start conservatively. A start this warm costs 10 to 20 seconds per mile for most runners before humidity is even counted.
  • •Pre-hydrate the day before, take water at every station from the first one, and pour some on your head and neck rather than just drinking.
  • •Humidity here is high. Sweat will not evaporate well, so wear the lightest, most open fabric you own and apply anti-chafe balm generously.
  • •It has rained on 4 of the last 10 race days. Pack a brimmed cap and a disposable poncho for the start, and consider a second pair of socks for the drop bag.
  • •Nothing new on race day: run your long runs in exactly what you plan to race in, including the socks.

Race-day gear picks

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Frequently asked questions

What is the weather usually like for the B.A.A. 10K?

Over 2016 to 2025 the start averaged 73°F (23°C) (feels like 75°F (24°C)) with 70% humidity and 7 mph wind, warming to about 77°F (25°C) by the finish. It rained measurably on 4 of those 10 race days. The coldest start was 66°F (19°C) in 2024; the warmest was 81°F (27°C) in 2022.

What should I wear for the B.A.A. 10K?

For a typical 73°F (23°C) start: Singlet or Tank, Running Shorts, Running Cap, Waterproof Jacket, Sunscreen. 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.

When is the next B.A.A. 10K?

The B.A.A. 10K is usually held on usually the fourth Sunday of June. The next expected date is Sunday, June 27, 2027. Confirm on the official site, since dates occasionally move.

How accurate is the race-day forecast?

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.

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