Flagtown has chilly winters and warm summers, with plenty of rain
A typical July afternoon reaches 87°, a January night drops to 22°, and about 21 inches of snow falls in a normal winter.
A year in Flagtown at a glance
Each month’s typical high and low, and what it brings.
What stands out about Flagtown’s climate
Read from where Flagtown sits among New Jersey’s towns. The page puts what stands out first.
Warmer than it used to be
The last 30 years in Flagtown averaged 2.4° warmer than the 1900s. The biggest change is in December (+4.1°).
A bigger shift than in 99% of U.S. towns.
Change by month
What a year in Flagtown feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
21 inches of snow, 49 of rain and melt
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
About 192 frost-free days a year
In half of years the last 32° night comes by April 16 and the first by October 27.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
Living with Flagtown’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
192 frost-free days. The last frost comes by Apr 16 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 27.
About 21" a winter over 6 days with an inch or more, most in January.
Months averaging under 55° run from October through April. Heating is 86% of the year’s heating-and-cooling load.
About 17 days a year reach 90°, and July afternoons average 87°.
The nicest months are May, June, September and October. 0.1 miles of trails are waiting.
Parks & trails →Normals are averages. Ice storms, nor’easters, floods and heat waves are on the natural hazards page.
Natural hazards →Flagtown and its neighbors
Branchburg has the coldest January nights next door (22°) and Neshanic the hottest July afternoons (87°). Tap a town to see its climate.
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.
How Flagtown compares
Against every U.S. town on TownTapestry, each counted once, with its place in New Jersey.
Flagtown 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 | 40° | 22° | 3.6" | 6.8" | 10 | 22° – 39° |
| February | 43° | 23° | 2.8" | 6.7" | 8 | 21° – 39° |
| March | 51° | 30° | 4.2" | 3.6" | 10 | 35° – 50° |
| April | 63° | 40° | 3.8" | 0.2" | 11 | 48° – 56° |
| May | 73° | 49° | 4.1" | 0 | 12 | 57° – 66° |
| June | 82° | 58° | 4.5" | 0 | 11 | 67° – 74° |
| July | 87° | 64° | 5.0" | 0 | 10 | 71° – 79° |
| August | 85° | 62° | 4.5" | 0 | 10 | 69° – 76° |
| September | 78° | 55° | 4.3" | 0 | 9 | 64° – 71° |
| October | 66° | 43° | 4.3" | 0.1" | 10 | 50° – 62° |
| November | 55° | 34° | 3.3" | 0.1" | 9 | 40° – 49° |
| December | 45° | 27° | 4.3" | 3.5" | 10 | 29° – 47° |
| Year | 64° | 42° | 48.6" | 21.0" | 121 |
Heating and cooling a home in Flagtown
86% of the work is heating, so the furnace matters far more than the air conditioner.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. Source: NOAA station normals.
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°. September is the most reliable, staying within 7°.
Common questions about Flagtown’s climate
What is the coldest month in Flagtown?
January, with a typical high of 40° and a low of 22°.
What is the hottest month in Flagtown?
July, with a typical high of 87° and a low of 64°. About 17 days a year reach 90°.
How much snow does Flagtown get?
About 21 inches in a normal winter, most of it in January.
When is the first frost in Flagtown?
In half of years the first 32° night comes by October 27, and the last spring frost by April 16.
What is the rainiest month in Flagtown?
July, with 5.0 inches of rain and melted snow. The year totals 49 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in Flagtown.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for Flagtown itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Bound Brook 2w, NJ (7 mi, snow) and Wertsville 4 Ne, NJ (7 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. Today’s forecast: National Weather Service.