Plymouth, CT climate
Plymouth has chilly, snowy winters and pleasant summers, with plenty of rain. A typical July afternoon reaches 82°, a January night drops to 17°, and about 39 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Plymouth feels like
Winter
Spring
Summer
Fall
Plymouth 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 | 35° | 17° | 3.8" | 11.1" | 10 | 13 | 17° – 32° |
| February | 38° | 18° | 3.3" | 11.8" | 9 | 13 | 14° – 34° |
| March | 46° | 26° | 4.4" | 5.5" | 10 | 9 | 29° – 45° |
| April | 59° | 35° | 4.4" | 0.5" | 11 | 0 | 43° – 52° |
| May | 69° | 46° | 4.0" | 0 | 12 | 0 | 53° – 62° |
| June | 77° | 55° | 4.7" | 0 | 11 | 0 | 63° – 69° |
| July | 82° | 60° | 4.4" | 0 | 11 | 0 | 66° – 75° |
| August | 80° | 59° | 4.5" | 0 | 10 | 0 | 66° – 73° |
| September | 73° | 52° | 4.7" | 0 | 9 | 0 | 59° – 67° |
| October | 62° | 40° | 5.3" | 0.6" | 10 | 0 | 47° – 57° |
| November | 50° | 31° | 4.1" | 0.8" | 9 | 1 | 36° – 45° |
| December | 39° | 23° | 4.6" | 8.3" | 11 | 7 | 24° – 42° |
| Year | 59° | 38° | 52.0" | 38.6" | 123 | 42 |
“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 Plymouth
Plymouth gets 52 inches of rain and melted snow a year. October is the wettest month and February the driest. Rain or snow falls on about 123 days a year. Snow covers the ground about 42 days of the year.
About 172 frost-free days a year
In half of years the last 32° night comes by April 25 and the first one by October 18. That leaves about 172 frost-free days for gardens, shorter than 58% of U.S. towns.
Heating and cooling a home in Plymouth
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Plymouth, 90% of that work is heating and 10% 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.
Plymouth and its neighbors
Plymouth borders 5 towns with climate data. January nights across them vary by 2.0°. Harwinton has the coldest January nights (16°) and Bristol the hottest July afternoons (84°). Plymouth’s January low is 17° and its July high 82°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Plymouth 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 Plymouth averaged 1.8° warmer than the 1900s. The biggest change is in December (+3.2°). The shift is larger than in 88% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Plymouth’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 14° to 34°. June is the most reliable, staying within 6°.
Common questions about Plymouth’s climate
What is the coldest month in Plymouth?
January, with a typical high of 35° and a low of 17°.
What is the hottest month in Plymouth?
July, with a typical high of 82° and a low of 60°. About 13 days a year reach 90°.
How much snow does Plymouth get?
About 39 inches in a normal winter, most of it in February.
When is the first frost in Plymouth?
In half of years the first 32° night comes by October 18, and the last spring frost by April 25.
What is the rainiest month in Plymouth?
October, with 5.3 inches of rain and melted snow. The year totals 52 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Plymouth itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Burlington, CT (10 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.