Southbury, CT climate
Southbury has chilly, snowy winters and warm summers, with plenty of rain. A typical July afternoon reaches 84°, a January night drops to 18°, and about 47 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decade7° warmer than normal today. The forecast high is 75°, and a typical Oct 1 in Southbury peaks around 68°.Live forecast: National Weather Service · Normal: NOAA 1991–2020
What a year in Southbury feels like
Winter
Spring
Summer
Fall
Southbury 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° | 18° | 3.4" | 11.3" | 12 | 15 | 18° – 33° |
| February | 39° | 19° | 3.0" | 13.7" | 10 | 15 | 16° – 36° |
| March | 47° | 27° | 4.0" | 10.3" | 12 | 9 | 31° – 46° |
| April | 60° | 37° | 4.1" | 1.4" | 10 | 1 | 44° – 52° |
| May | 71° | 47° | 3.9" | 0 | 12 | 0 | 54° – 64° |
| June | 79° | 56° | 4.4" | 0 | 11 | 0 | 65° – 71° |
| July | 84° | 62° | 4.4" | 0 | 10 | 0 | 68° – 77° |
| August | 82° | 60° | 4.3" | 0 | 9 | 0 | 68° – 75° |
| September | 75° | 53° | 4.5" | 0 | 10 | 0 | 60° – 68° |
| October | 63° | 41° | 4.7" | 0 | 9 | 0 | 48° – 59° |
| November | 51° | 32° | 3.8" | 1.5" | 10 | 1 | 37° – 46° |
| December | 41° | 24° | 4.2" | 8.6" | 11 | 9 | 26° – 44° |
| Year | 61° | 40° | 48.6" | 46.8" | 125 | 49 |
“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 Southbury
Southbury gets 49 inches of rain and melted snow a year. October is the wettest month and February the driest. Rain or snow falls on about 125 days a year. Snow covers the ground about 49 days of the year.
About 181 frost-free days a year
In half of years the last 32° night comes by April 20 and the first one by October 20. That leaves about 181 frost-free days for gardens, longer than 54% of U.S. towns.
Heating and cooling a home in Southbury
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Southbury, 87% of that work is heating and 13% 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.
Southbury and its neighbors
Southbury borders 6 towns with climate data. January nights across them vary by 1.7°. Roxbury has the coldest January nights (17°) and Newtown the hottest July afternoons (83°). Southbury’s January low is 18° and its July high 84°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Southbury 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 Southbury averaged 1.8° warmer than the 1900s. The biggest change is in December (+3.2°). The shift is larger than in 85% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Southbury’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 16° to 36°. June is the most reliable, staying within 6°.
Common questions about Southbury’s climate
What is the coldest month in Southbury?
January, with a typical high of 36° and a low of 18°.
What is the hottest month in Southbury?
July, with a typical high of 84° and a low of 62°. About 20 days a year reach 90°.
How much snow does Southbury get?
About 47 inches in a normal winter, most of it in February.
When is the first frost in Southbury?
In half of years the first 32° night comes by October 20, and the last spring frost by April 20.
What is the rainiest month in Southbury?
October, with 4.7 inches of rain and melted snow. The year totals 49 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Southbury itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Woodbury, CT (5 mi, snow) and Danbury, CT (11 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.