Photo: AEMoreira042281 · CC BY-SA 3.0Wet weather: 49 inches of rain and melted snow a year in Dunellen, more than in 79% of U.S. towns
In July the day’s top temperature is typically 87°. Summer afternoons here are warmer than in 61% of U.S. towns. December has warmed most since 1901–2000, part of a 2.3° rise. Long walks are most pleasant from April to June and September to October, when afternoons reach 63–82°.
A year in Dunellen at a glance
Each month’s typical high and low, and what it brings.
What stands out about Dunellen’s climate
Compared with towns across the U.S., with Dunellen’s place in New Jersey beside it.
What a year in Dunellen feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 198 frost-free days a year
In half of years the last 32° night comes by April 11 and the first by October 28. Frost and day counts come from NOAA’s station at Plainfield, NJ, 3 miles from the town’s center, at about the same height.
The 2023 USDA map puts Dunellen’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 4°. 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 49 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 Dunellen
81% of the work is heating. 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 Plainfield, NJ.
Living with Dunellen’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
198 frost-free days in zone 7a. The last frost comes by Apr 11 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 28.
Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October. 0.9 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Dunellen from natural hazards, river flooding is the largest share (84%); heat waves, cold waves, winter storms and ice storms together are 5%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Dunellen and its neighbors
Every town next door is within a degree of Dunellen in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Dunellen’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 |
|---|---|---|---|---|
| Dunellen, NJ | 22° | 87° | 49" | 21" |
| Cynthiana, KY | 24° | 87° | 48" | 16" |
| North Vernon, IN | 23° | 86° | 48" | 17" |
| Amelia, OH | 23° | 86° | 46" | 23" |
| Ilchester, MD | 25° | 88° | 47" | 19" |
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 Dunellen averaged 2.3° warmer than the 1900s. The biggest change is in December (+3.8°).
A bigger shift than in 97% 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 Dunellen compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Dunellen’s place among New Jersey’s.
Dunellen weather by month
Highs, lows and precipitation from NOAA’s grid at Dunellen’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 | 40° | 22° | 3.5" | 6.8" | 10 | 23° – 38° |
| February | 43° | 24° | 2.9" | 6.7" | 8 | 22° – 40° |
| March | 51° | 31° | 4.2" | 3.6" | 10 | 35° – 50° |
| April | 63° | 40° | 3.8" | 0.2" | 11 | 48° – 56° |
| May | 73° | 50° | 4.1" | 0.0" | 12 | 57° – 67° |
| June | 82° | 59° | 4.4" | 0.0" | 11 | 67° – 74° |
| July | 87° | 65° | 5.0" | 0.0" | 10 | 71° – 79° |
| August | 85° | 63° | 4.5" | 0.0" | 10 | 69° – 77° |
| September | 78° | 56° | 4.3" | 0.0" | 9 | 64° – 72° |
| October | 66° | 44° | 4.3" | 0.1" | 10 | 50° – 61° |
| November | 55° | 35° | 3.3" | 0.1" | 9 | 40° – 50° |
| December | 45° | 28° | 4.3" | 3.5" | 10 | 29° – 48° |
| Year | 64° | 43° | 48.6" | 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 48°. June is the most reliable, staying within 7°.
Where Dunellen’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 Dunellen’s center.
- Snow: Bound Brook 2w, NJ.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Plainfield, NJ, 3 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 Dunellen’s climate
What is the weather like in Dunellen?
A typical July afternoon reaches 87°, a January night drops to 22°, and about 21 inches of snow falls in a normal winter. Milder January nights than 53% of U.S. towns; hotter July afternoons than 61% of U.S. towns.
How cold does it get in Dunellen in winter?
January nights average 22°. About 103 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 23°.
How much snow does Dunellen 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 Dunellen?
July, with a typical high of 87° and a low of 65°. About 29 days a year reach 90° and 1 reach 100° (Plainfield, NJ).
When is the first and last frost in Dunellen?
In half of years the last spring frost (32°) comes by April 11 and the first fall frost by October 28, about 198 frost-free days, at Plainfield, NJ.
What growing zone is Dunellen in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 4°.
What is the best time of year to visit Dunellen?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Dunellen getting warmer?
Yes: 1991–2020 averaged 2.3° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 97% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Dunellen.
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.