Photo: Chevy111 · CC BY-SA 4.0Acton reaches 100° on about 24 days a year, more than 97% of U.S. towns
A typical July afternoon reaches 93°, a January night drops to 37°, and snow is almost unheard of.
A year in Acton at a glance
Each month’s typical high and low, and what it brings.
What stands out about Acton’s climate
Compared with towns across the U.S., with Acton’s place in California beside it.
What a year in Acton feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 258 frost-free days a year
In half of years the last 32° night comes by March 13 and the first by December 1. Frost and day counts come from NOAA’s station at Pearblossom, CA, 16 miles from the town’s center, 170 ft lower.
The 2023 USDA map puts Acton’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 23°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 11 inches of rain a year
February is the wettest month and August the driest. Rain falls on about 32 days a year. Snow is rare: about 0.0" in a normal year at Acton Escondido Fc261, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Acton
53% of the work is heating. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Pearblossom, CA.
Living with Acton’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
258 frost-free days in zone 9a. The last frost comes by Mar 13 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Dec 1.
Months with highs of 62–84° and lows of 40° or more: March, April, May, October and November. 63 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Acton from natural hazards, avalanches are the largest share (37%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Acton and its neighbors
Palmdale has the coldest January nights next door (35°, 2° colder) and Palmdale the hottest July afternoons (96°, 3° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Acton’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Acton, CA | 37° | 93° | 11" | 0.0" |
| Benson, AZ | 34° | 94° | 14" | 1.2" |
| Chaparral, NM | 31° | 95° | 9" | 0.0" |
| Fort Stockton, TX | 33° | 96° | 13" | 1.4" |
| Ashland, OR | 31° | 91° | 19" | 0.5" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Acton averaged 2.0° warmer than the 1900s. The biggest change is in January (+2.8°).
A bigger shift than in 90% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Acton compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Acton’s place among California’s.
Acton weather by month
Highs, lows and precipitation from NOAA’s grid at Acton’s center; snow, wet days and snow on the ground from Acton Escondido Fc261, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 58° | 37° | 2.3" | 0.0" | 5 | 0 | 44° – 54° |
| February | 60° | 38° | 2.6" | 0.0" | 6 | 0 | 41° – 56° |
| March | 65° | 41° | 1.8" | 0.0" | 5 | 0 | 46° – 60° |
| April | 70° | 44° | 0.7" | 0.0" | 2 | 0 | 51° – 62° |
| May | 77° | 50° | 0.2" | 0.0" | 1 | 0 | 55° – 71° |
| June | 87° | 57° | 0.0" | 0.0" | 0 | 0 | 65° – 77° |
| July | 93° | 63° | 0.0" | 0.0" | 0 | 0 | 74° – 83° |
| August | 93° | 63° | 0.0" | 0.0" | 0 | 0 | 75° – 82° |
| September | 88° | 58° | 0.1" | 0.0" | 1 | 0 | 68° – 78° |
| October | 77° | 50° | 0.5" | 0.0" | 2 | 0 | 59° – 69° |
| November | 66° | 41° | 0.6" | 0.0" | 3 | 0 | 46° – 59° |
| December | 57° | 36° | 1.7" | 0.0" | 5 | 0 | 41° – 52° |
| Year | 74° | 48° | 10.6" | 0.0" | 32 | 0 |
How much a month can swing
A normal is an average. May swings the most: from 1991 to 2020 its average ranged from 55° to 71°. August is the most reliable, staying within 7°.
Where Acton’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Acton’s center.
- Snow: Acton Escondido Fc261, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Pearblossom, CA, 16 miles from the town’s center, 170 ft lower; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Acton’s climate
What is the weather like in Acton?
A typical July afternoon reaches 93°, a January night drops to 37°, and snow is almost unheard of. Milder January nights than 85% of U.S. towns; hotter July afternoons than 91% of U.S. towns.
How cold does it get in Acton in winter?
December nights average 36°. About 26 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 41°.
How much snow does Acton get?
About 0.0 inches in a normal winter at Acton Escondido Fc261, CA, so most winters see none.
How hot does it get in Acton?
July, with a typical high of 93° and a low of 63°. About 107 days a year reach 90° and 24 reach 100° (Pearblossom, CA).
When is the first and last frost in Acton?
In half of years the last spring frost (32°) comes by March 13 and the first fall frost by December 1, about 258 frost-free days, at Pearblossom, CA.
What growing zone is Acton in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 23°.
What is the best time of year to visit Acton?
By one simple rule (highs of 62–84° and lows of 40° or more), March, April, May, October and November. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Acton getting warmer?
Yes: 1991–2020 averaged 2.0° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 90% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Acton.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.