Photo: Mr. Matté (if there is an issue with this image, contact me using this image's Commons talk page, my Commons user talk page, or my English Wikipedia user talk page; I'll know about it a lot faster) · CC BY-SA 4.0More precipitation falls on Green Knoll than on 83% of U.S. towns: 50 inches a year
The warmest part of a July day comes in at 86° on average. Seasons differ by 64°, from the coldest nights to the warmest afternoons. Seedlings are safe outdoors from about April 30, with the first autumn frost due around October 20.
A year in Green Knoll at a glance
Each month’s typical high and low, and what it brings.
What stands out about Green Knoll’s climate
Compared with towns across the U.S., with Green Knoll’s place in New Jersey beside it.
What a year in Green Knoll feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 172 frost-free days a year
In half of years the last 32° night comes by April 30 and the first by October 20. Frost and day counts come from NOAA’s station at Somerville 4 Nw, NJ, 2.2 miles from the town’s center, at about the same height.
The 2023 USDA map puts Green Knoll’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 1°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 21 inches of snow a winter
Snow, measured at Bound Brook 2w, NJ, is heaviest from January through February, about 7 inches a month. Precipitation (rain plus melted snow) adds up to 50 inches a year; July is the wettest month and February the driest. Rain or snow falls on about 121 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Green Knoll
89% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Somerville 4 Nw, NJ.
Living with Green Knoll’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
172 frost-free days in zone 7a. The last frost comes by Apr 30 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 20.
Months with highs of 62–84° and lows of 40° or more: May, June, August, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Green Knoll from natural hazards, river flooding is the largest share (79%); heat waves, cold waves, winter storms and ice storms together are 7%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Green Knoll and its neighbors
Every town next door is within a degree of Green Knoll in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Green Knoll’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Green Knoll, NJ | 22° | 86° | 50" | 21" |
| North Vernon, IN | 23° | 86° | 48" | 17" |
| Clarksburg, WV | 23° | 85° | 47" | 24" |
| Walton, KY | 23° | 86° | 47" | 23" |
| Delhi Hills, OH | 23° | 86° | 46" | 23" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Green Knoll averaged 2.3° warmer than the 1900s. The biggest change is in December (+3.9°).
A bigger shift than in 98% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Green Knoll compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Green Knoll’s place among New Jersey’s.
Green Knoll weather by month
Highs, lows and precipitation from NOAA’s grid at Green Knoll’s center; snow, wet days and snow on the ground from Bound Brook 2w, NJ. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 39° | 22° | 3.6" | 6.8" | 10 | 22° – 38° |
| February | 42° | 23° | 2.9" | 6.7" | 8 | 21° – 39° |
| March | 50° | 30° | 4.2" | 3.6" | 10 | 34° – 49° |
| April | 63° | 39° | 3.9" | 0.2" | 11 | 47° – 56° |
| May | 72° | 49° | 4.2" | 0.0" | 12 | 56° – 66° |
| June | 81° | 58° | 4.6" | 0.0" | 11 | 66° – 73° |
| July | 86° | 64° | 5.1" | 0.0" | 10 | 70° – 79° |
| August | 84° | 62° | 4.6" | 0.0" | 10 | 68° – 76° |
| September | 77° | 55° | 4.4" | 0.0" | 9 | 63° – 71° |
| October | 65° | 43° | 4.5" | 0.1" | 10 | 49° – 61° |
| November | 54° | 34° | 3.4" | 0.1" | 9 | 39° – 49° |
| December | 44° | 27° | 4.4" | 3.5" | 10 | 29° – 47° |
| Year | 63° | 42° | 49.6" | 21.0" | 121 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 29° to 47°. June is the most reliable, staying within 7°.
Where Green Knoll’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Green Knoll’s center.
- Snow: Bound Brook 2w, NJ.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Somerville 4 Nw, NJ, 2.2 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Green Knoll’s climate
What is the weather like in Green Knoll?
A typical July afternoon reaches 86°, a January night drops to 22°, and about 21 inches of snow falls in a normal winter. Colder January nights than 51% of U.S. towns; hotter July afternoons than 55% of U.S. towns.
How cold does it get in Green Knoll in winter?
January nights average 22°. About 137 nights a year reach 32° or below and 2 reach 0° or below. In the coldest January of the last 30 years the month averaged 22°.
How much snow does Green Knoll get?
About 21 inches in a normal winter at Bound Brook 2w, NJ, heaviest from January through February, about 7 inches a month.
How hot does it get in Green Knoll?
July, with a typical high of 86° and a low of 64°. About 16 days a year reach 90° (Somerville 4 Nw, NJ).
When is the first and last frost in Green Knoll?
In half of years the last spring frost (32°) comes by April 30 and the first fall frost by October 20, about 172 frost-free days, at Somerville 4 Nw, NJ.
What growing zone is Green Knoll in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 1°.
What is the best time of year to visit Green Knoll?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Green Knoll getting warmer?
Yes: 1991–2020 averaged 2.3° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 98% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Green Knoll.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.