Acton, MT climate
Acton has chilly, snowy winters and warm summers, with very little rain. A typical July afternoon reaches 86°, a January night drops to 16°, and about 35 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Acton feels like
Winter
Spring
Summer
Fall
Acton weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 36° | 16° | 0.5" | 7.5" | 5 | 18 | 16° – 37° |
| February | 40° | 17° | 0.4" | 4.7" | 5 | 10 | 8° – 40° |
| March | 49° | 25° | 0.7" | 4.9" | 6 | 5 | 25° – 45° |
| April | 56° | 32° | 1.5" | 3.2" | 9 | 1 | 38° – 49° |
| May | 66° | 41° | 2.3" | 0.1" | 11 | 0 | 49° – 58° |
| June | 76° | 50° | 2.3" | 0 | 10 | 0 | 57° – 68° |
| July | 86° | 56° | 1.3" | 0 | 7 | 0 | 61° – 77° |
| August | 85° | 54° | 1.0" | 0 | 5 | 0 | 63° – 74° |
| September | 74° | 45° | 1.1" | 0 | 6 | 0 | 55° – 65° |
| October | 59° | 34° | 1.2" | 1.7" | 7 | 1 | 38° – 52° |
| November | 46° | 24° | 0.6" | 3.1" | 6 | 5 | 24° – 44° |
| December | 37° | 17° | 0.5" | 9.8" | 5 | 11 | 16° – 35° |
| Year | 59° | 34° | 13.4" | 35.0" | 81 | 52 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Acton
Acton gets 13 inches of rain and melted snow a year. May is the wettest month and February the driest. Rain or snow falls on about 81 days a year. Snow covers the ground about 52 days of the year.
About 142 frost-free days a year
In half of years the last 32° night comes by May 10 and the first one by October 1. That leaves about 142 frost-free days for gardens, shorter than 88% of U.S. towns.
Heating and cooling a home in Acton
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Acton, 93% of that work is heating and 7% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
How Acton compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Acton averaged 1.3° warmer than the 1900s. The biggest change is in January (+4.1°). The shift is larger than in 58% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Acton’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 8° to 40°. May is the most reliable, staying within 9°.
Common questions about Acton’s climate
What is the coldest month in Acton?
January, with a typical high of 36° and a low of 16°.
What is the hottest month in Acton?
July, with a typical high of 86° and a low of 56°. About 41 days a year reach 90°.
How much snow does Acton get?
About 35 inches in a normal winter, most of it in December.
When is the first frost in Acton?
In half of years the first 32° night comes by October 1, and the last spring frost by May 10.
What is the rainiest month in Acton?
May, with 2.3 inches of rain and melted snow. The year totals 13 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Acton itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Billings Wtp, MT (14 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.