Granby, CT climate
Granby has chilly, snowy winters and warm summers, with plenty of rain. A typical July afternoon reaches 85°, a January night drops to 17°, and about 52 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Granby feels like
Winter
Spring
Summer
Fall
Granby 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 | 35° | 17° | 3.5" | 14.2" | 11 | 18° – 33° |
| February | 39° | 19° | 3.2" | 14.8" | 11 | 15° – 35° |
| March | 47° | 26° | 4.1" | 9.4" | 11 | 30° – 46° |
| April | 60° | 36° | 4.3" | 1.1" | 12 | 43° – 53° |
| May | 72° | 47° | 3.9" | 0 | 12 | 54° – 65° |
| June | 80° | 56° | 4.5" | 0 | 12 | 65° – 71° |
| July | 85° | 61° | 4.3" | 0 | 11 | 68° – 77° |
| August | 83° | 60° | 4.4" | 0 | 10 | 67° – 75° |
| September | 75° | 52° | 4.7" | 0 | 9 | 61° – 68° |
| October | 63° | 41° | 5.1" | 0.7" | 11 | 48° – 58° |
| November | 51° | 32° | 3.9" | 1.4" | 10 | 37° – 46° |
| December | 40° | 23° | 4.5" | 10.1" | 12 | 25° – 42° |
| Year | 61° | 39° | 50.2" | 51.7" | 130 |
“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 Granby
Granby gets 50 inches of rain and melted snow a year. October is the wettest month and February the driest. Rain or snow falls on about 130 days a year.
About 177 frost-free days a year
In half of years the last 32° night comes by April 21 and the first one by October 16. That leaves about 177 frost-free days for gardens, shorter than 51% of U.S. towns.
Heating and cooling a home in Granby
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Granby, 88% of that work is heating and 12% 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.
Granby and its neighbors
Granby borders 7 towns with climate data. January nights across them vary by 3.1°. Hartland has the coldest January nights (15°) and East Granby the hottest July afternoons (85°). Granby’s January low is 17° and its July high 85°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Granby 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 Granby averaged 1.7° warmer than the 1900s. The biggest change is in December (+3.4°). The shift is larger than in 83% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Granby’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 15° to 35°. June is the most reliable, staying within 6°.
Common questions about Granby’s climate
What is the coldest month in Granby?
January, with a typical high of 35° and a low of 17°.
What is the hottest month in Granby?
July, with a typical high of 85° and a low of 61°. About 20 days a year reach 90°.
How much snow does Granby get?
About 52 inches in a normal winter, most of it in February.
When is the first frost in Granby?
In half of years the first 32° night comes by October 16, and the last spring frost by April 21.
What is the rainiest month in Granby?
October, with 5.1 inches of rain and melted snow. The year totals 50 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Granby itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Hartford Bradley Intl Airport, CT (8 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.