Boston in August

In August, Boston averages 27°C (81°F) during the day and 17°C (63°F) at night, with around 9 days of rain (94 mm total).

High season

Conditions are warm and beach-friendly. Occasional showers are likely but won't dominate.

It's peak hurricane season in Boston during August. Travel is possible but expect storm risk, possible flight disruption, and generally lower travel insurance coverage.

27°C
Avg high
17°C
Avg low
9
Rain days
94 mm
Rainfall

How August compares to the rest of the year in Boston

2nd
warmest month of the 12
11th
wettest month of the 12
8%
of yearly rainfall falls in August
13 h 55 min
daylight on the 15th

August is one of the warmest months in Boston (2nd of 12) and one of the driest months (11th of 12). Daytime temperature runs 12°C above the annual average (15°C). August runs 1°C cooler than July (28°C) and cools 4°C in September (23°C).

August sunrise & sunset in Boston

🌅
Sunrise (15th)
5:51 AM
🌇
Sunset (15th)
7:46 PM
Day length
13 h 55 min

Times shown for Boston local time (America/New_York), calculated for the 15th of August. They shift by a few minutes day to day across the month.

Photography light in Boston — August

Golden-hour and blue-hour windows for the 15th of August, in Boston's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).

🌅 Blue hour (AM)
4:51 AM – 5:31 AM
🌄 Golden hour (AM)
5:31 AM – 6:31 AM
🌇 Golden hour (PM)
7:06 PM – 8:06 PM
🌆 Blue hour (PM)
8:06 PM – 8:46 PM
Milky Way galactic core
Fair
Core only briefly above the horizon — a marginal month even from dark sites near Boston.

📅 When to book — Boston in August

Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on August's tier (High season) and Boston's popularity.

✈ Flights — lead time
3-4 months
Prices are above off-season but not the absolute peak. Tuesday/Wednesday departures are usually cheaper than weekend ones. ⚠ Peak hazard season — book flexible-change tickets and travel insurance with weather-disruption coverage.
🏨 Lodging — lead time
3-5 months
Wide selection still available at this lead time. Premium properties book first; consider 'last-minute deal' availability at 2-week mark if your dates are flexible.

Crowds & pricing — August in Boston

High season

This is a busy month in Boston — not the absolute peak, but tourist numbers are clearly elevated. You'll feel it at headline attractions on weekends and in the historic centre, though side streets and lesser-known sights stay manageable. Prices are above off-season but not at their summit. A good week for first-time visitors who want everything open without the worst of the crush.

Why this tier: comfortable tourism weather Northern Hemisphere summer holidays peak hazard season (1 active)

Sun & mosquito risk — August in Boston

☀️ UV Index (noon, 15th)
10.9
Very high
Limit sun exposure between 11 AM and 3 PM; SPF 30-50, reapply every 90 minutes outdoors.
🦟 Mosquito risk
●●●●○
High
Peak mosquito activity. DEET 30%+, long sleeves at dawn/dusk, sleep under nets if rural.

UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.

Sea temperature in Boston — August

19.6°C (67°F)
cool
swimmable but bracing — wetsuit helps for long sessions

Across the year Boston's sea swings from 3.5°C (February) to 19.6°C (August) — August sits at 19.6°C.

Boston in other months

MonthAvg highAvg lowRainfallRain daysSnow days
January 2°C / 36°F -6°C / 21°F 88 mm 10 10
February 3°C / 37°F -5°C / 23°F 88 mm 10 9
March 7°C / 45°F -1°C / 30°F 104 mm 11 5
April 14°C / 57°F 4°C / 39°F 92 mm 11 1
May 19°C / 66°F 9°C / 48°F 88 mm 11 0
June 25°C / 77°F 15°C / 59°F 95 mm 11 0
July 28°C / 82°F 18°C / 64°F 84 mm 9 0
August 27°C / 81°F 17°C / 63°F 94 mm 9 0
September 23°C / 73°F 13°C / 55°F 85 mm 9 0
October 17°C / 63°F 7°C / 45°F 96 mm 10 0
November 11°C / 52°F 2°C / 36°F 108 mm 11 1
December 5°C / 41°F -3°C / 27°F 106 mm 12 7

Other cities with similar August weather

🌍 See the full ranked list of climate twins for Boston in August →

Frequently asked questions

How hot is Boston in August?

In August, Boston averages a high of 27°C (81°F) and a low of 17°C (63°F) — generally warm.

Does it rain a lot in Boston in August?

August sees occasional rain in Boston, with about 9 rainy days on average.

Is August a good time to visit Boston?

August is warm. It suits travelers who are comfortable with warm weather; check the month-by-month ranking to compare it against the rest of the year.

What should I pack for Boston in August?

Pack lightweight, breathable clothing, sunglasses and sunscreen. See the full August packing list for Boston for a complete, climate-based checklist.

Open Boston on the interactive map

Check the live 10-day forecast and sunrise/sunset.