Precipitation in South Wilton tops that of 78% of U.S. towns: 48 inches a year
In July the day’s top temperature is typically 84°. Winter and summer sit 63° apart. Plan time outside from May to June and August to October, when highs sit at 64–82°.
A year in South Wilton at a glance
Each month’s typical high and low, and what it brings.
What stands out about South Wilton’s climate
Compared with towns across the U.S., with South Wilton’s place in Connecticut beside it.
What a year in South Wilton feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 188 frost-free days a year
In half of years the last 32° night comes by April 17 and the first by October 23. Frost and day counts come from NOAA’s station at Stamford 5 N, CT, 7 miles from the town’s center, at about the same height.
The 2023 USDA map puts South Wilton’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 2°. 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 34 inches of snow a winter
Snow, measured at Stamford 5 N, CT, falls mostly in February. Precipitation (rain plus melted snow) adds up to 48 inches a year; October is the wettest month and February the driest. Rain or snow falls on about 124 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in South Wilton
86% 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 Stamford 5 N, CT.
Living with South Wilton’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
188 frost-free days in zone 7a. The last frost comes by Apr 17 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 23.
Months with highs of 62–84° and lows of 40° or more: May, June, August, September and October.
Parks & trails →Of the yearly building losses FEMA expects in South Wilton from natural hazards, river flooding is the largest share (73%); heat waves, cold waves, winter storms and ice storms together are 2%. Normals are averages; the hazards page covers the extremes.
Natural hazards →South Wilton and its neighbors
Every town next door is within a degree of South Wilton in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like South Wilton’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 |
|---|---|---|---|---|
| South Wilton, CT | 21° | 84° | 48" | 34" |
| Manchester, MD | 22° | 84° | 47" | 34" |
| New Freedom, PA | 21° | 84° | 48" | 29" |
| Buckhannon, WV | 23° | 83° | 50" | 39" |
| Cumberland, IN | 20° | 85° | 44" | 27" |
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 South Wilton averaged 2.1° warmer than the 1900s. The biggest change is in December (+3.4°).
A bigger shift than in 92% 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 South Wilton compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with South Wilton’s place among Connecticut’s.
South Wilton weather by month
Highs, lows and precipitation from NOAA’s grid at South Wilton’s center; snow, wet days and snow on the ground from Stamford 5 N, CT. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 38° | 21° | 3.5" | 9.1" | 11 | 21° – 36° |
| February | 40° | 22° | 3.0" | 11.9" | 8 | 19° – 37° |
| March | 48° | 29° | 4.2" | 5.9" | 10 | 33° – 47° |
| April | 60° | 39° | 4.2" | 0.5" | 12 | 45° – 54° |
| May | 71° | 48° | 3.9" | 0.0" | 12 | 55° – 64° |
| June | 79° | 58° | 4.5" | 0.0" | 12 | 66° – 71° |
| July | 84° | 64° | 4.1" | 0.0" | 9 | 69° – 78° |
| August | 82° | 62° | 4.1" | 0.0" | 9 | 68° – 76° |
| September | 75° | 55° | 4.4" | 0.0" | 9 | 62° – 69° |
| October | 64° | 44° | 4.5" | 0.0" | 10 | 50° – 61° |
| November | 53° | 34° | 3.7" | 0.8" | 10 | 39° – 48° |
| December | 43° | 27° | 4.2" | 5.8" | 11 | 27° – 46° |
| Year | 61° | 42° | 48.4" | 34.0" | 124 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 19° to 37°. June is the most reliable, staying within 6°.
Where South Wilton’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 South Wilton’s center.
- Snow: Stamford 5 N, CT.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Stamford 5 N, CT, 7 miles from the town’s center, at about the same height; 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 South Wilton’s climate
What is the weather like in South Wilton?
A typical July afternoon reaches 84°, a January night drops to 21°, and about 34 inches of snow falls in a normal winter. Colder January nights than 54% of U.S. towns; cooler July afternoons than 58% of U.S. towns.
How cold does it get in South Wilton in winter?
January nights average 21°. About 119 nights a year reach 32° or below and 2 reach 0° or below. In the coldest January of the last 30 years the month averaged 21°.
How much snow does South Wilton get?
About 34 inches in a normal winter at Stamford 5 N, CT, most of it in February.
How hot does it get in South Wilton?
July, with a typical high of 84° and a low of 64°. About 18 days a year reach 90° (Stamford 5 N, CT).
When is the first and last frost in South Wilton?
In half of years the last spring frost (32°) comes by April 17 and the first fall frost by October 23, about 188 frost-free days, at Stamford 5 N, CT.
What growing zone is South Wilton in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 2°.
What is the best time of year to visit South Wilton?
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 South Wilton getting warmer?
Yes: 1991–2020 averaged 2.1° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 92% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in South Wilton.
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.