Photo: Daderot · Public domainWilliamstown’s winters are colder than most of the U.S.; July afternoons average 81°
A typical July afternoon reaches 81°, a January night drops to 14°.
A year in Williamstown at a glance
Each month’s typical high and low, and what it brings.
What stands out about Williamstown’s climate
Compared with towns across the U.S., with Williamstown’s place in Massachusetts beside it.
What a year in Williamstown feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 147 frost-free days a year
In half of years the last 32° night comes by May 10 and the first by October 4. Frost and day counts come from NOAA’s station at North Adams Harriman Airport, 2.6 miles from the town’s center, 480 ft lower.
The 2023 USDA map puts Williamstown’s center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −11°. 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 44 inches of rain a year
June is the wettest month and February the driest.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Williamstown
95% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at North Adams Harriman Airport.
Living with Williamstown’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
147 frost-free days in zone 5b. The last frost comes by May 10 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 4.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 110 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Williamstown from natural hazards, river flooding is the largest share (82%); heat waves, cold waves, winter storms and ice storms together are 6%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Williamstown and its neighbors
Every town next door is within a degree of Williamstown in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
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 Williamstown averaged 1.7° warmer than the 1900s. The biggest change is in December (+3.3°).
A bigger shift than in 70% 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 Williamstown compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Williamstown’s place among Massachusetts’.
Williamstown weather by month
Highs, lows and precipitation from NOAA’s grid at Williamstown’s center. 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 32° | 14° | 2.9" | 12° – 31° |
| February | 34° | 15° | 2.4" | 10° – 31° |
| March | 43° | 23° | 3.1" | 26° – 43° |
| April | 57° | 33° | 3.3" | 39° – 50° |
| May | 69° | 44° | 3.7" | 51° – 62° |
| June | 77° | 53° | 4.5" | 62° – 69° |
| July | 81° | 58° | 4.4" | 65° – 74° |
| August | 79° | 56° | 4.2" | 65° – 72° |
| September | 72° | 48° | 4.4" | 56° – 64° |
| October | 60° | 38° | 4.2" | 44° – 55° |
| November | 48° | 29° | 3.3" | 34° – 44° |
| December | 37° | 21° | 3.4" | 21° – 40° |
| Year | 57° | 36° | 43.6" |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 10° to 31°. August is the most reliable, staying within 7°.
Where Williamstown’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 Williamstown’s center.
- Frost, freezing nights, 90° and 100° days, heating and cooling: North Adams Harriman Airport, 2.6 miles from the town’s center, 480 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 Williamstown’s climate
What is the weather like in Williamstown?
A typical July afternoon reaches 81°, a January night drops to 14°. Colder January nights than 88% of U.S. towns; cooler July afternoons than 87% of U.S. towns.
How cold does it get in Williamstown in winter?
January nights average 14°. About 149 nights a year reach 32° or below and 9 reach 0° or below. In the coldest January of the last 30 years the month averaged 12°.
How hot does it get in Williamstown?
July, with a typical high of 81° and a low of 58°. About 4 days a year reach 90° (North Adams Harriman Airport).
When is the first and last frost in Williamstown?
In half of years the last spring frost (32°) comes by May 10 and the first fall frost by October 4, about 147 frost-free days, at North Adams Harriman Airport.
What growing zone is Williamstown in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −11°.
What is the best time of year to visit Williamstown?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Williamstown getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 70% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Williamstown.
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.