Greenwich, NJ climate
Greenwich has chilly winters and warm summers. A typical July afternoon reaches 86°, a January night drops to 27°, and about 12 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Greenwich feels like
Winter
Spring
Summer
Fall
Greenwich 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 | 42° | 27° | 3.1" | 3.9" | 10 | 5 | 27° – 42° |
| February | 45° | 28° | 2.7" | 3.6" | 10 | 6 | 26° – 44° |
| March | 53° | 34° | 4.1" | 1.8" | 11 | 2 | 38° – 52° |
| April | 64° | 44° | 3.4" | 0.2" | 11 | 0 | 50° – 58° |
| May | 73° | 53° | 3.3" | 0 | 11 | 0 | 58° – 69° |
| June | 81° | 63° | 4.3" | 0 | 10 | 0 | 68° – 77° |
| July | 86° | 68° | 4.7" | 0 | 10 | 0 | 72° – 81° |
| August | 84° | 66° | 4.5" | 0 | 9 | 0 | 71° – 79° |
| September | 78° | 60° | 4.0" | 0 | 8 | 0 | 66° – 73° |
| October | 67° | 48° | 3.8" | 0 | 9 | 0 | 53° – 64° |
| November | 56° | 38° | 3.2" | 0.1" | 9 | 0 | 41° – 51° |
| December | 47° | 31° | 3.9" | 2.2" | 10 | 2 | 31° – 51° |
| Year | 65° | 47° | 45.0" | 11.8" | 117 | 15 |
“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 Greenwich
Greenwich gets 45 inches of rain and melted snow a year. July is the wettest month and February the driest. Rain or snow falls on about 117 days a year. Snow covers the ground about 15 days of the year.
About 205 frost-free days a year
In half of years the last 32° night comes by April 10 and the first one by November 1. That leaves about 205 frost-free days for gardens, longer than 75% of U.S. towns.
Heating and cooling a home in Greenwich
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Greenwich, 81% of that work is heating and 19% 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.
Greenwich and its neighbors
Greenwich borders 4 towns with climate data. January nights across them vary by 1.8°. Hopewell has the coldest January nights (25°) and Stow Creek the hottest July afternoons (86°). Greenwich’s January low is 27° and its July high 86°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Greenwich 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 Greenwich averaged 2.0° warmer than the 1900s. The biggest change is in December (+3.5°). The shift is larger than in 95% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Greenwich’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 31° to 51°. September is the most reliable, staying within 7°.
Common questions about Greenwich’s climate
What is the coldest month in Greenwich?
January, with a typical high of 42° and a low of 27°.
What is the hottest month in Greenwich?
July, with a typical high of 86° and a low of 68°. About 25 days a year reach 90°.
How much snow does Greenwich get?
About 12 inches in a normal winter, most of it in January.
When is the first frost in Greenwich?
In half of years the first 32° night comes by November 1, and the last spring frost by April 10.
What is the rainiest month in Greenwich?
July, with 4.7 inches of rain and melted snow. The year totals 45 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Greenwich itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Seabrook Farms, NJ (10 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.