Guilford, CT climate
Guilford has chilly winters and pleasant summers. A typical July afternoon reaches 84°, a January night drops to 20°.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Guilford feels like
Winter
Spring
Summer
Fall
Guilford weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 38° | 20° | 3.5" | 20° – 35° |
| February | 40° | 21° | 3.1" | 17° – 37° |
| March | 47° | 28° | 4.2" | 32° – 46° |
| April | 59° | 37° | 4.3" | 44° – 53° |
| May | 69° | 47° | 3.6" | 53° – 63° |
| June | 78° | 57° | 4.2" | 64° – 70° |
| July | 84° | 63° | 3.9" | 69° – 77° |
| August | 82° | 62° | 3.7" | 68° – 76° |
| September | 75° | 55° | 4.1" | 62° – 69° |
| October | 64° | 43° | 4.5" | 50° – 60° |
| November | 52° | 34° | 3.8" | 38° – 47° |
| December | 42° | 26° | 4.2" | 28° – 45° |
| Year | 61° | 41° | 47.0" |
“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 Guilford
Guilford gets 47 inches of rain and melted snow a year. October is the wettest month and February the driest.
About 191 frost-free days a year
In half of years the last 32° night comes by April 18 and the first one by October 26. That leaves about 191 frost-free days for gardens, longer than 65% of U.S. towns.
Heating and cooling a home in Guilford
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Guilford, 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.
Guilford and its neighbors
Guilford borders 4 towns with climate data. January nights across them vary by 3.7°. Durham has both the coldest January nights (19°) and the hottest July afternoons (84°). Guilford’s January low is 20° and its July high 84°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Guilford 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 Guilford averaged 1.7° warmer than the 1900s. The biggest change is in December (+3.3°). The shift is larger than in 84% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Guilford’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 17° to 37°. June is the most reliable, staying within 6°.
Common questions about Guilford’s climate
What is the coldest month in Guilford?
January, with a typical high of 38° and a low of 20°.
What is the hottest month in Guilford?
July, with a typical high of 84° and a low of 63°. About 14 days a year reach 90°.
When is the first frost in Guilford?
In half of years the first 32° night comes by October 26, and the last spring frost by April 18.
What is the rainiest month in Guilford?
October, with 4.5 inches of rain and melted snow. The year totals 47 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Guilford itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Mt Carmel, 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.