Photo: John Phelan · CC BY 3.0Wet weather: 49 inches of rain and melted snow a year in Southwick, more than in 82% of U.S. towns
The coldest hours of a January night bottom out at 17° on average. Winter and summer sit 68° apart. By January nights alone, it runs colder than 76% of U.S. towns. Seedlings are safe outdoors from about April 28, with the first autumn frost due around October 17.
A year in Southwick at a glance
Each month’s typical high and low, and what it brings.
What stands out about Southwick’s climate
Compared with towns across the U.S., with Southwick’s place in Massachusetts beside it.
What a year in Southwick feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 171 frost-free days a year
In half of years the last 32° night comes by April 28 and the first by October 17. Frost and day counts come from NOAA’s station at Westfield 3 Sw, MA, 3 miles from the town’s center, 110 ft higher.
The 2023 USDA map puts Southwick’s center in zone 6b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −5°. 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 52 inches of snow a winter
Snow, measured at Hartford Bradley International Airport, is heaviest from January through February, about 15 inches a month. Precipitation (rain plus melted snow) adds up to 49 inches a year; October is the wettest month and February the driest. Rain or snow falls on about 130 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Southwick
91% 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 Westfield 3 Sw, MA.
Living with Southwick’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
171 frost-free days in zone 6b. The last frost comes by Apr 28 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 17.
Months with highs of 62–84° and lows of 40° or more: May, June, August, September and October. 33 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Southwick from natural hazards, river flooding is the largest share (70%); heat waves, cold waves, winter storms and ice storms together are 6%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Southwick and its neighbors
Granville has the coldest January nights next door (15°, 2° colder). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Southwick’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 |
|---|---|---|---|---|
| Southwick, MA | 17° | 85° | 49" | 52" |
| Easton, PA | 20° | 86° | 48" | 41" |
| Buckhannon, WV | 23° | 83° | 50" | 39" |
| Manchester, MD | 22° | 84° | 47" | 34" |
| Cortland, OH | 18° | 83° | 43" | 68" |
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 Southwick averaged 1.7° warmer than the 1900s. The biggest change is in December (+3.3°).
A bigger shift than in 73% 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 Southwick compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Southwick’s place among Massachusetts’.
Southwick weather by month
Highs, lows and precipitation from NOAA’s grid at Southwick’s center; snow, wet days and snow on the ground from Hartford Bradley International Airport. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 35° | 17° | 3.4" | 14.2" | 11 | 17° – 33° |
| February | 38° | 19° | 3.2" | 14.8" | 11 | 15° – 35° |
| March | 47° | 26° | 4.0" | 9.4" | 11 | 30° – 46° |
| April | 60° | 36° | 4.2" | 1.1" | 12 | 43° – 53° |
| May | 72° | 47° | 3.8" | 0.0" | 12 | 54° – 65° |
| June | 80° | 56° | 4.6" | 0.0" | 12 | 65° – 71° |
| July | 85° | 61° | 4.2" | 0.0" | 11 | 68° – 77° |
| August | 83° | 60° | 4.3" | 0.0" | 10 | 68° – 75° |
| September | 75° | 52° | 4.6" | 0.0" | 9 | 61° – 68° |
| October | 63° | 40° | 5.0" | 0.7" | 11 | 47° – 58° |
| November | 51° | 31° | 3.8" | 1.4" | 10 | 37° – 46° |
| December | 40° | 23° | 4.3" | 10.1" | 12 | 25° – 42° |
| Year | 61° | 39° | 49.3" | 51.7" | 130 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 15° to 35°. June is the most reliable, staying within 6°.
Where Southwick’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 Southwick’s center.
- Snow: Hartford Bradley International Airport.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Westfield 3 Sw, MA, 3 miles from the town’s center, 110 ft higher; 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 Southwick’s climate
What is the weather like in Southwick?
A typical July afternoon reaches 85°, a January night drops to 17°, and about 52 inches of snow falls in a normal winter. Colder January nights than 76% of U.S. towns; cooler July afternoons than 52% of U.S. towns.
How cold does it get in Southwick in winter?
January nights average 17°. About 143 nights a year reach 32° or below and 5 reach 0° or below. In the coldest January of the last 30 years the month averaged 17°.
How much snow does Southwick get?
About 52 inches in a normal winter at Hartford Bradley International Airport, heaviest from January through February, about 15 inches a month.
How hot does it get in Southwick?
July, with a typical high of 85° and a low of 61°. About 14 days a year reach 90° (Westfield 3 Sw, MA).
When is the first and last frost in Southwick?
In half of years the last spring frost (32°) comes by April 28 and the first fall frost by October 17, about 171 frost-free days, at Westfield 3 Sw, MA.
What growing zone is Southwick in?
Zone 6b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −5°.
What is the best time of year to visit Southwick?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Southwick getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 73% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Southwick.
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.