Princeton Junction has chilly winters and warm summers
A typical July afternoon reaches 87°, a January night drops to 24°, and about 24 inches of snow falls in a normal winter.
A year in Princeton Junction at a glance
Each month’s typical high and low, and what it brings.
What stands out about Princeton Junction’s climate
Read from where Princeton Junction sits among New Jersey’s towns. The page puts what stands out first.
Living with Princeton Junction’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
173 frost-free days. The last frost comes by Apr 25 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 16.
About 24" a winter over 7 days with an inch or more, most in February. Snow covers the ground about 24 days a year.
Months averaging under 55° run from November through April. Heating is 85% of the year’s heating-and-cooling load.
About 26 days a year reach 90°, and July afternoons average 87°.
The nicest months are April, May, June, September and October. 1.9 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 →What a year in Princeton Junction feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
24 inches of snow, 47 of rain and melt
July is the wettest month and February the driest. Rain or snow falls on about 126 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
About 173 frost-free days a year
In half of years the last 32° night comes by April 25 and the first by October 16.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
Princeton Junction and its neighbors
Plainsboro has the coldest January nights next door (23°) and West Windsor 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.
Warmer than it used to be
The last 30 years in Princeton Junction averaged 2.2° warmer than the 1900s. The biggest change is in December (+3.8°).
A bigger shift than in 98% of U.S. towns.
Change by month
How Princeton Junction compares
Against every U.S. town on TownTapestry, each counted once, with its place in New Jersey.
Princeton Junction 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 | 41° | 24° | 3.5" | 5.8" | 11 | 8 | 24° – 40° |
| February | 44° | 25° | 2.7" | 8.0" | 9 | 9 | 23° – 41° |
| March | 52° | 32° | 4.1" | 4.6" | 11 | 4 | 36° – 50° |
| April | 64° | 40° | 3.6" | 0.6" | 12 | 0 | 48° – 56° |
| May | 73° | 50° | 3.9" | 0 | 12 | 0 | 57° – 67° |
| June | 82° | 60° | 4.4" | 0 | 12 | 0 | 67° – 75° |
| July | 87° | 65° | 5.0" | 0 | 11 | 0 | 71° – 80° |
| August | 85° | 63° | 4.3" | 0 | 10 | 0 | 70° – 77° |
| September | 78° | 56° | 4.1" | 0 | 9 | 0 | 65° – 72° |
| October | 67° | 45° | 4.1" | 0 | 10 | 0 | 51° – 63° |
| November | 55° | 35° | 3.3" | 0.3" | 9 | 0 | 41° – 50° |
| December | 46° | 28° | 4.2" | 4.4" | 11 | 3 | 30° – 49° |
| Year | 64° | 44° | 47.0" | 23.7" | 126 | 24 |
Heating and cooling a home in Princeton Junction
85% 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 30° to 49°. September is the most reliable, staying within 7°.
Common questions about Princeton Junction’s climate
What is the coldest month in Princeton Junction?
January, with a typical high of 41° and a low of 24°.
What is the hottest month in Princeton Junction?
July, with a typical high of 87° and a low of 65°. About 26 days a year reach 90°.
How much snow does Princeton Junction get?
About 24 inches in a normal winter, most of it in February.
When is the first frost in Princeton Junction?
In half of years the first 32° night comes by October 16, and the last spring frost by April 25.
What is the rainiest month in Princeton Junction?
July, with 5.0 inches of rain and melted snow. The year totals 47 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in Princeton Junction.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for Princeton Junction itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Hightstown 2 W, NJ (5 mi) away. 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.