Dorchester in Summer
In summer (June, July and August), Dorchester sees average daytime highs around 77°F and overnight lows near 63°F, with 9.6 in of rain over about 29 wet days across the season. It is the warmest season of the year and the driest season of the year.
Over the season highs climb from about 69°F in early June to 76°F by late August. The sky is clear or mostly clear about 30% of the time across summer, and the air most often feels humid.
Summer is Dorchester's best season of the year to visit on our travel score. For the whole year in context, see Dorchester's year-round climate.
- Avg daytime high
- 77°F
- warmest season of the year
- Avg overnight low
- 63°F
- Rainfall
- 9.6 in
- 29 wet days
- Avg wind
- 7 mph
- Travel score
- 6.8
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Dorchester in Summer
Over the season highs climb from about 69°F in early June to 76°F by late August.
A typical summer day in Dorchester reaches about 77°F and drops to 63°F overnight. The warmest of the three months is July, the coolest June.
How summer really feels in Dorchester
Once humidity and wind are folded in, summer brings about 0 days that feel above 90°F and 0 that feel at or below 32°F.
summer sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Dorchester 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 (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 36° / 24° | 3.7 | 10 | 5.6 | 9.3 | 0.0 |
| Feb | 38° / 25° | 3.3 | 8.8 | 5.1 | 10.3 | 0.0 |
| Mar | 44° / 31° | 4.6 | 11.1 | 4.6 | 11.6 | 0.8 |
| Apr | 54° / 41° | 3.9 | 11 | 1 | 13.1 | 3.2 |
| May | 64° / 50° | 3.2 | 10.6 | 0 | 14.4 | 5.5 |
| Jun | 73° / 59° | 3.4 | 10.1 | 0 | 15 | 6.6 |
| Jul | 79° / 65° | 2.9 | 9.6 | 0 | 14.8 | 6.7 |
| Aug | 78° / 65° | 3.4 | 9.2 | 0 | 13.7 | 7.0 |
| Sep | 71° / 58° | 3.5 | 8.2 | 0 | 12.3 | 6.9 |
| Oct | 61° / 48° | 4.3 | 9.8 | 0.1 | 10.8 | 5.1 |
| Nov | 50° / 38° | 3.7 | 9.6 | 0.8 | 9.6 | 2.4 |
| Dec | 41° / 30° | 4.5 | 10.8 | 4.3 | 9 | 0.3 |
Cloud cover in Summer
The sky is clear or mostly clear about 30% of the time across summer.
Chance of precipitation in Summer
Dorchester gets around 9.6 in of rain over 29 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 7 mph across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 54 min in early June to 13 h 06 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 5.7 kWh/m².
Hazard calendar for Dorchester
In summer, Dorchester overlaps its atlantic hurricane season. The full year is below, with each hazard's peak months called out.
Dorchester sits in the Atlantic hurricane belt; the season peaks August–October.
Is summer a good time to visit Dorchester?
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 Dorchester for sightseeing.
What to pack for Dorchester in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Dorchester sees daytime highs around 77°F and nights near 63°F. Worth packing: light clothes, rain gear and sun protection. About 29 days see rain.
Sea temperature near Dorchester in Summer
The nearest coast averages about 63°F 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 12 mi away) is warmest in August at about 66°F and coldest in February near 38°F.
The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 41 | 38 | 38 | 42 | 50 | 58 | 65 | 66 | 63 | 56 | 50 | 46 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Cool | Cool | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 41 | Bracing |
| Feb | 38 | Bracing |
| Mar | 38 | Bracing |
| Apr | 42 | Bracing |
| May | 50 | Bracing |
| Jun | 58 | Bracing |
| Jul | 65 | Cool |
| Aug | 66 | Cool |
| Sep | 63 | Cool |
| Oct | 56 | Bracing |
| Nov | 50 | Bracing |
| Dec | 46 | Bracing |
UV index in Dorchester 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 Dorchester peaks around July 10 at about 7 (very 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 8 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 3 | 4 | 5 | 7 | 7 | 7 | 5 | 6 | 3 | 2 | 1 |
| Level | Low | Moderate | Moderate | High | Very high | Very high | Very high | Moderate | High | Moderate | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 3 | Moderate |
| Mar | 4 | Moderate |
| Apr | 5 | High |
| May | 7 | Very high |
| Jun | 7 | Very high |
| Jul | 7 | Very high |
| Aug | 5 | Moderate |
| Sep | 6 | High |
| Oct | 3 | Moderate |
| Nov | 2 | Moderate |
| Dec | 1 | Low |
Air quality in Dorchester in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Dorchester is worst in July — around 16 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (November, 8 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 10 | 13 | 14 | 14 | 15 | 15 | 16 | 14 | 12 | 10 | 8 | 10 |
| Level | Good | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 10 | Good |
| Feb | 13 | Moderate |
| Mar | 14 | Moderate |
| Apr | 14 | Moderate |
| May | 15 | Moderate |
| Jun | 15 | Moderate |
| Jul | 16 | Moderate |
| Aug | 14 | Moderate |
| Sep | 12 | Good |
| Oct | 10 | Good |
| Nov | 8 | Good |
| Dec | 10 | Good |
Where is Dorchester?
Dorchester sits at 42.3°N, 71.1°W, 118 ft above sea level, in United States. The nearest listed city is Ashmont, 1.2 mi away.
Topography around Dorchester
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Dorchester.
Within 2 miles, the terrain around Dorchester has only modest variations in elevation — a maximum elevation change of 210 ft around an average of 72 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 633 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,165 ft.
The land around Dorchester is covered by artificial surfaces (56%) and trees (30%) within 2 miles, trees (44%), artificial surfaces (28%) and water (22%) within 10 miles, and trees (60%) and water (30%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- 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 Dorchester (42.2973°, -71.0745°, elevation 118 ft), 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.