Acton in Fall
In fall (September, October and November), Acton sees average daytime highs around 62°F and overnight lows near 44°F, with 10.4 in of precipitation over about 26 wet days across the season. It is the 2nd-warmest season and the 2nd-wettest season.
Over the season highs ease from about 78°F in early September to 46°F by late November. The sky is clear or mostly clear about 37% of the time across fall, and the air most often feels dry.
Fall is Acton's 2nd-best season to visit on our travel score. For the whole year in context, see Acton's year-round climate.
- Avg daytime high
- 62°F
- 2nd-warmest season
- Avg overnight low
- 44°F
- Precipitation
- 10.4 in
- 26 wet days
- Avg wind
- 7 mph
- Travel score
- 4.9
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Acton in Fall
Over the season highs ease from about 78°F in early September to 46°F by late November.
A typical fall day in Acton reaches about 62°F and drops to 44°F overnight. The warmest of the three months is September, the coolest November.
How fall really feels in Acton
Once humidity and wind are folded in, fall brings about 0 days that feel above 90°F and 26 that feel at or below 32°F.
The story in fall is cold — wind chill drags the overnight "feels like" below the raw low.
Acton weather by month
How the three fall months (September, October and November) 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 | 35° / 20° | 3.2 | 9.6 | 6.2 | 9.2 | 0.0 |
| Feb | 37° / 22° | 3.0 | 8.5 | 5.7 | 10.3 | 0.0 |
| Mar | 45° / 29° | 4.1 | 11.1 | 5.1 | 11.6 | 1.1 |
| Apr | 57° / 39° | 3.6 | 10.5 | 1.2 | 13.1 | 4.0 |
| May | 67° / 49° | 3.1 | 10.5 | 0 | 14.4 | 6.0 |
| Jun | 77° / 58° | 3.5 | 10.7 | 0 | 15.1 | 6.5 |
| Jul | 83° / 64° | 3.2 | 10.3 | 0 | 14.8 | 5.8 |
| Aug | 81° / 62° | 3.4 | 9.6 | 0 | 13.7 | 6.5 |
| Sep | 73° / 55° | 3.4 | 8 | 0 | 12.3 | 7.0 |
| Oct | 61° / 44° | 3.7 | 9.3 | 0.2 | 10.8 | 5.3 |
| Nov | 50° / 34° | 3.3 | 9.1 | 1.1 | 9.6 | 2.3 |
| Dec | 40° / 26° | 4.1 | 10.3 | 5 | 8.9 | 0.1 |
Cloud cover in Fall
The sky is clear or mostly clear about 37% of the time across fall.
Chance of precipitation in Fall
Acton gets around 10.4 in of rain and snow over 26 wet days across fall. The line is the day-by-day chance of measurable precipitation.
Humidity in Fall
Most of fall feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Fall
Winds average 7 mph across fall.
Sunrise & sunset in Fall
Daylight runs from about 13 hours in early September to 9 h 06 min by late November. The lit band spans sunrise to sunset each day.
Solar energy in Fall
Average shortwave solar energy reaching the ground each day across fall, about 3.0 kWh/m².
Hazard calendar for Acton
In fall, Acton overlaps its atlantic hurricane season. The full year is below, with each hazard's peak months called out.
Acton sits in the Atlantic hurricane belt; the season peaks August–October.
Is fall a good time to visit Acton?
Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
fall is a reasonable time to visit Acton for sightseeing.
What to pack for Acton in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Acton sees daytime highs around 62°F and nights near 44°F. Pack a warm layer. Worth having: light clothes and rain gear. About 26 days see rain.
Sea temperature near Acton in Fall
The nearest coast averages about 56°F across fall — 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 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 Acton in Fall
Clear-sky midday UV across fall averages around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Acton 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 December 23 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 Acton in Fall
Average fine-particle pollution (PM2.5) through the year — so you can see where fall falls, not just the annual average.
Air quality in Acton is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.0× 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) | 9 | 13 | 13 | 13 | 14 | 13 | 16 | 14 | 11 | 9 | 8 | 9 |
| Level | Good | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 9 | Good |
| Feb | 13 | Moderate |
| Mar | 13 | Moderate |
| Apr | 13 | Moderate |
| May | 14 | Moderate |
| Jun | 13 | Moderate |
| Jul | 16 | Moderate |
| Aug | 14 | Moderate |
| Sep | 11 | Good |
| Oct | 9 | Good |
| Nov | 8 | Good |
| Dec | 9 | Good |
Where is Acton?
Acton sits at 42.5°N, 71.4°W, 266 ft above sea level, in United States. The nearest listed city is Concord, 4.3 mi away.
Topography around Acton
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Acton.
Within 2 miles, the terrain around Acton has only modest variations in elevation — a maximum elevation change of 315 ft around an average of 236 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 574 ft; within 50 miles, large variations in elevation — a maximum elevation change of 3,176 ft.
The land around Acton is covered by trees (86%) within 2 miles, trees (84%) within 10 miles, and trees (77%) 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 Acton (42.4851°, -71.4328°, elevation 266 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.