South Wilton has chilly, snowy winters and warm summers, with plenty of rain
A typical July afternoon reaches 84°, a January night drops to 21°, and about 34 inches of snow falls in a normal winter.
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
Read from where South Wilton sits among Connecticut’s towns. The page puts what stands out first.
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 95% of U.S. towns.
Change by month
What a year in South Wilton feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
34 inches of snow, 48 of rain and melt
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
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.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
Living with South Wilton’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
188 frost-free days. 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.
About 34" a winter over 10 days with an inch or more, most in February.
Months averaging under 55° run from October through April. Heating is 86% of the year’s heating-and-cooling load.
About 18 days a year reach 90°, and July afternoons average 84°.
The nicest months are May, June, August, September and October.
Parks & trails →Normals are averages. Ice storms, nor’easters, floods and heat waves are on the natural hazards page.
Natural hazards →South Wilton and its neighbors
Wilton has the coldest January nights next door (20°) and Norwalk the hottest July afternoons (85°). 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.
How South Wilton compares
Against every U.S. town on TownTapestry, each counted once, with its place in Connecticut.
South Wilton 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 | 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 | 12 | 55° – 64° |
| June | 79° | 58° | 4.5" | 0 | 12 | 66° – 71° |
| July | 84° | 64° | 4.1" | 0 | 9 | 69° – 78° |
| August | 82° | 62° | 4.1" | 0 | 9 | 68° – 76° |
| September | 75° | 55° | 4.4" | 0 | 9 | 62° – 69° |
| October | 64° | 44° | 4.5" | 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 |
Heating and cooling a home in South Wilton
86% of the work is heating, so the furnace matters far more than the air conditioner.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. Source: NOAA station normals.
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°.
Common questions about South Wilton’s climate
What is the coldest month in South Wilton?
January, with a typical high of 38° and a low of 21°.
What is the hottest month in South Wilton?
July, with a typical high of 84° and a low of 64°. About 18 days a year reach 90°.
How much snow does South Wilton get?
About 34 inches in a normal winter, most of it in February.
When is the first frost in South Wilton?
In half of years the first 32° night comes by October 23, and the last spring frost by April 17.
What is the rainiest month in South Wilton?
October, with 4.5 inches of rain and melted snow. The year totals 48 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in South Wilton.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for South Wilton itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Stamford 5 N, CT (7 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000. Today’s forecast: National Weather Service.