Boston in Summer
In summer (June, July and August), Boston sees average daytime highs around 20°C and overnight lows near 13°C, with 186 mm of rain over about 33 wet days across the season. It is the warmest season of the year and the wettest season of the year.
Over the season highs climb from about 17°C in early June to 20°C by late August. The sky is clear or mostly clear about 13% of the time across summer, and the air most often feels dry.
Summer is Boston's best season of the year to visit on our travel score. For the whole year in context, see Boston's year-round climate.
- Avg daytime high
- 20°C
- warmest season of the year
- Avg overnight low
- 13°C
- Rainfall
- 186 mm
- 33 wet days
- Avg wind
- 15 km/h
- Travel score
- 5.9
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Boston in Summer
Over the season highs climb from about 17°C in early June to 20°C by late August.
A typical summer day in Boston reaches about 20°C and drops to 13°C overnight. The warmest of the three months is July, the coolest June.
How summer really feels in Boston
Once humidity and wind are folded in, summer brings about 0 days that feel above 32°C and 0 that feel at or below 0°C.
summer sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Boston weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 7° / 3° | 49 | 11.3 | 0.8 | 7.9 | 0.9 |
| Feb | 8° / 3° | 38 | 9.1 | 1.1 | 9.5 | 1.1 |
| Mar | 10° / 4° | 42 | 10.1 | 0.6 | 11.5 | 2.1 |
| Apr | 12° / 6° | 46 | 10.5 | 0.1 | 13.6 | 3.3 |
| May | 15° / 9° | 50 | 10 | 0 | 15.5 | 4.6 |
| Jun | 18° / 11° | 61 | 11.1 | 0 | 16.6 | 5.5 |
| Jul | 21° / 13° | 62 | 11.1 | 0 | 16.2 | 6.1 |
| Aug | 21° / 13° | 63 | 10.9 | 0 | 14.5 | 6.1 |
| Sep | 18° / 11° | 55 | 9.5 | 0 | 12.4 | 5.6 |
| Oct | 14° / 8° | 60 | 10.6 | 0 | 10.3 | 3.9 |
| Nov | 10° / 5° | 55 | 11.1 | 0.2 | 8.4 | 2.1 |
| Dec | 7° / 3° | 51 | 11 | 0.9 | 7.4 | 1.0 |
Cloud cover in Summer
The sky is clear or mostly clear about 13% of the time across summer.
Chance of precipitation in Summer
Boston gets around 186 mm of rain over 33 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 15 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 16 h 18 min in early June to 13 h 30 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 4.7 kWh/m².
Is summer a good time to visit Boston?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Boston for sightseeing.
What to pack for Boston in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Boston sees daytime highs around 20°C and nights near 13°C. Worth packing: rain gear and sun protection. About 33 days see rain.
Sea temperature near Boston in Summer
The nearest coast averages about 16°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 29 km away) is warmest in August at about 18°C and coldest in February near 5°C.
The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 6 | 5 | 6 | 8 | 11 | 14 | 17 | 18 | 16 | 13 | 10 | 7 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Cool | Cool | Bracing | Bracing | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 6 | Bracing |
| Feb | 5 | Bracing |
| Mar | 6 | Bracing |
| Apr | 8 | Bracing |
| May | 11 | Bracing |
| Jun | 14 | Bracing |
| Jul | 17 | Cool |
| Aug | 18 | Cool |
| Sep | 16 | Cool |
| Oct | 13 | Bracing |
| Nov | 10 | Bracing |
| Dec | 7 | Bracing |
UV index in Boston in Summer
Clear-sky midday UV across summer averages around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Boston peaks around August 11 at about 6 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 1 | 3 | 3 | 6 | 6 | 6 | 6 | 4 | 2 | 1 | 1 |
| Level | Low | Low | Moderate | Moderate | High | High | High | High | Moderate | Low | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 1 | Low |
| Mar | 3 | Moderate |
| Apr | 3 | Moderate |
| May | 6 | High |
| Jun | 6 | High |
| Jul | 6 | High |
| Aug | 6 | High |
| Sep | 4 | Moderate |
| Oct | 2 | Low |
| Nov | 1 | Low |
| Dec | 1 | Low |
Where is Boston?
Boston sits at 53.0°N, 0.0°W, 9 m above sea level, in United Kingdom. The nearest listed city is Spalding, 23 km away.
Topography around Boston
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Boston.
Within 3 km, the terrain around Boston has only modest variations in elevation — a maximum elevation change of 21 m around an average of 2 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 23 m; within 80 km, only modest variations in elevation — a maximum elevation change of 249 m.
The land around Boston is covered by cropland (38%), artificial surfaces (26%) and grassland (23%) within 3 km, cropland (68%) within 16 km, and cropland (54%) within 80 km.
United Kingdom travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type D / G / M
- 230 V · 50 Hz
- Prices
- ≈ 89% of US
- price level, 2025
- GDP per capita
- $57,602
- 2025
- Happiness
- 6.7 / 10
- World Happiness, 2025
- Safe drinking water
- 100%
- of population, 2024
- Homicide rate
- 1.1
- per 100k, 2021
- Road deaths
- 3.2
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Boston (52.9763°, -0.0266°, elevation 9 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.