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Shaded-relief map of Plainsboro, New Jersey: rivers, roads, the city limits and where the water drains.
NEW JERSEY · MIDDLESEX COUNTY

Plainsboro

24,558 people, 90 ft above sea level in Middlesex County.

90 ftElevation, city center
24,558People, 2024 estimate
12 sq miLand area
Sunny 45°
Sunny now Dew point 30° · WNW 8 mph · high 47°
City of Plainsboro River Interstate 2 miles
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The Plainsboro plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.

MILE1
TODAY

Today in Plainsboro

NWS forecast and National Blend of Models · updated 3:00 PM EST
RIGHT NOW Trenton-Mercer Airport (KTTN) · 3:53 PM
Sunny
45° Sunny Feels like 41° · high of 47° near 4 PM
WindWNW 8 mphno gusts
Humidity56%rising to 96% by morning
Pressure29.83 in →steady
Visibility10 mihaze-free
CloudsClear
UV index—no forecast
Dew point 30° · Dryabout the same for three days
DryComfortableStickyMuggyOppressive
NEXT RAIN
Clear
Not this weeknone in the forecast for a week
LIKELY AMOUNT—nothing expected
LAST RAINNov. 120.46 in · 2 dry days
ALERTS & OUTLOOKS
No watches or warnings for Middlesex County
NWS Mount Holly and the Storm Prediction Center · checked 4:16 PM
SUN & MOON
↑ 6:43 AM4:42 PM ↓
9 h 59 m of daylight, 2 minutes less than yesterday
Waxing crescent, 25% lit. Next full moon: Nov. 24.
AIR & POLLEN
23
GOODAir quality index · ozone
Tomorrow: 35, good. No pollen source yet.

The next three days, hour by hour

Sky: clear, cloudy, night Rain likely National Blend of Models
SATURDAY, NOV. 14
SUNDAY, NOV. 15
MONDAY, NOV. 16
TUESDAY, NOV. 17
4p
7p
10p
1a
4a
7a
10a
1p
4p
7p
10p
1a
4a
7a
10a
1p
4p
7p
10p
1a
4a
7a
10a
1p
mostly cloudy night
partly cloudy night
partly cloudy night
mostly clear night
mostly clear night
mostly sunny
mostly sunny
partly cloudy day
partly cloudy night
mostly clear night
mostly clear night
mostly clear night
mostly clear night
mostly sunny
mostly sunny
mostly sunny
mostly clear night
mostly clear night
mostly clear night
clear night
mostly clear night
mostly sunny
clear day
clear day
TEMPERATURE °F
47°
33°
53°
32°
54°
31°
CHANCE OF RAIN
50%
WIND, MPH
9
7
8
9
9
10
13
12
8
7
7
6
6
7
9
8
7
5
4
4
5
5
6
7
HOW IT FEELS · DEW POINT
Dry: dew points 29 to 36°

The next seven days, and how sure we are

Forecast, with the range 8 in 10 ensemble members agree on Normal, about 55° / 37°
SAT Nov. 14 Mostly cloudy Mostly cloudy
47° 32°
0% rain — WNW 10 A
SUN Nov. 15 Partly cloudy Partly cloudy
53° 30°
0% rain — NNW 11 A
MON Nov. 16 Mostly sunny Mostly sunny
55° 30°
0% rain — NNW 8 B
TUE Nov. 17 Sunny Sunny
57° 31°
0% rain — W 6 A
WED Nov. 18 Sunny Sunny
60° 32°
0% rain — W 5 A
THU Nov. 19 Mostly sunny Mostly sunny
62° 36°
0% rain — SW 3 A
FRI Nov. 20 Mostly sunny Mostly sunny
63° 38°
0% rain — NW 3 B
How sure are we? AModels agree: highs within 4° BSome spread: within 8° CWide spread: check back
Range from the National Blend of Models percentiles · graded on Forecast Scores
AIR MAIL

Where today’s air came from

The air arriving over Plainsboro about 5,000 feet above the ground was over British Columbia three days ago, and over the Great Lakes a day ago, about 2,930 miles back along its path. It came down from about 11,000 feet up, warming and drying as it sank. It feels dry all the same. Traced back 72 hours through NOAA’s hourly RAP analyses and the GFS beyond them, nine paths at each of three heights.

THIS WEEK IN 1993 Nov. 16, 1993

The hottest this week has been

79° on Nov. 16, 1993, the hottest reading for this week of the year since 1891. Next is 77° in 2020.

77°
79°
20201993
Source: NOAA RCC-ACIS, the Hightstown 2 W record since 1891.
MILE2
THE GROUND

What Plainsboro stands on

Plainsboro’s center stands about 90 ft above sea level. Within three miles the land runs from 50 ft to 170 ft, a difference of 120 ft: gently rolling country. The highest named summit within 15 miles is Sourland Mountain, about 640 ft, 11 miles northwest.

The section below crosses 13 rock units mapped at the surface.

Plainsboro, cut in half from northwest to southeast

A section northwest to southeast, 24 miles through the town center
0 ft200 ft400 ft PLAINSBORO90 ftHigh point of the line560 ftMillstone Riverabout 40 ftTwin Rivers110 ftMillstone250 ft ← NWMillstone · SE →

Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 37×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.

Rock at the surface along the line

Magothy Formation

Sand. Age: Late Cretaceous, 84 to 87 million years old. About 5 mi of the line.

Passaic Formation

Siltstone. Age: Late Triassic to Early Jurassic, 175 to 237 million years old. About 3 mi of the line.

Lockatong Formation

Siltstone-mudstone, sandstone-mudstone. Age: Late Triassic, 202 to 237 million years old. About 3 mi of the line.

Englishtown Formation

Sand, clay. Age: Late Cretaceous, 72 to 84 million years old. About 2 mi of the line.

Diabase

Plutonic. Age: Jurassic, 145 to 202 million years old. About 2 mi of the line.

Stockton Formation

Arkose. Age: Late Triassic, 202 to 237 million years old. About 2 mi of the line.

From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 7 smaller units along the line are not listed.

Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.

MILE3
THE WATER

Where Plainsboro’s rain goes

A raindrop that lands in Plainsboro reaches New York Harbor and the Atlantic Ocean by way of Devils Brook, the Millstone and the Raritan: about 45 river miles.

THE WAY DOWN, TO SCALE
Plainsboro≈ 45 mi · New York Harbor and the Atlantic Ocean
FROM THE CENTER OF PLAINSBORO ≈ 45 mi to New York Harbor and the Atlantic Ocean Devils Brook → Millstone → Raritan

Traced down the USGS NHDPlus V2.1 river network from the Census center point of Plainsboro; river miles along the main stem, rounded.

MILE5
THE ALMANAC

Plainsboro’s year

1991–2020 normals · records since 1891 · Hightstown 2 W, 5 mi south-southeast

Plainsboro has a hot-summer humid continental climate. Summer afternoons average 87° in July; winter nights fall to about 21° in January. A normal year brings about 24 inches of snow; with the rain, that comes to about 48 inches of water.

40°21°43°23°51°30°63°39°73°48°82°58°87°63°85°61°78°54°66°42°55°33°46°27° JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 12 TODAY PLAINSBORO 47.5 in rain and snowmelt
Normal high to low, by month Record high to low, by day Rain by month Freezing
July, average87° / 63°high / low, the warmest month
January, average40° / 21°high / low, the coldest month
Rain and melted snow47.5 inwettest months: July and June
Snow a year23.7 insnowiest: February
Hottest on record105°FJuly 9, 1936
Coldest on record−16°FJanuary 28, 1935
Wettest day on record7.89 inAugust 28, 2011
Snowiest day on record17.0 inFebruary 12, 1983
90° days a year26very few reach 100°
Nights at or below 32°114and 15 days that stay below freezing
Climate typeHot-summer humid continentalKöppen Dfa

AROUND THE RING

1Freeze seasonfrom the first fall freeze, about Oct. 18, to the last in spring, about April 23 (median dates)
2Lows below freezingNov. 17 to March 26; normal lows fall below 32°
NOVEMBER 14 IN THE RECORD

On November 14 Plainsboro normally reaches 56° and falls to 33°. The record high is 72°, in 1959; the record low 15°, in 2019. The most rain on this date, 1.89 in, fell in 1972.

MONTH BY MONTH
JanFebMarAprMayJunJulAugSepOctNovDec
Normal high40°43°51°63°73°82°87°85°78°66°55°46°
Normal low21°23°30°39°48°58°63°61°54°42°33°27°
Rain and melt, in3.462.614.283.674.074.634.824.294.153.983.264.23
Snow, inches5.88.04.60.60.00.00.00.00.00.00.34.4
Record high73° (1932)77° (2018)88° (1998)95° (2002)97° (1914)100° (2025)105° (1936)102° (2001)103° (1953)95° (1941)83° (2024)76° (1998)
Record low−16° (1935)−11° (1907)2° (2015)10° (1923)28° (1978)35° (1938)42° (1929)40° (1986)31° (1963)22° (1969)0° (1938)−12° (1917)

Normals 1991–2020 and records since 1891 at Hightstown 2 W, 5 miles south-southeast. NOAA, through RCC-ACIS.

MILE7
ON THE NETWORK

Around Plainsboro on the Forecast Network

Neighboring plates

Newark NJ · 34 MI 34 miles northeast Philadelphia PA · 37 MI 37 miles southwest New York NY · 41 MI 41 miles northeast Hempstead NY · 55 MI 55 miles east Brookhaven NY · 92 MI 92 miles northeast Baltimore MD · 129 MI 129 miles southwest
FORECASTCITY
Map of Plainsboro, New Jersey. Explore the plate
NEW JERSEY · MIDDLESEX

Plainsboro

24,558 people, 90 ft above sea level in Middlesex County.

90 ftElevation
24,558People
12 sq miLand
Sunny 45°
SunnyDew point 30°
1

Today in Plainsboro

NEXT 15 HOURS
Now mostly cloudy day 47° 1%
7p partly cloudy night 40° 3%
10p partly cloudy night 38° 2%
1a partly cloudy night 36° 1%
4a mostly clear night 34° 1%
7a mostly sunny 33° 0%
Clear
NEXT RAINNone this week
→
Sat0%
Mostly cloudy Mostly cloudy
32
47
A
Sun0%
Partly cloudy Partly cloudy
30
53
A
Mon0%
Mostly sunny Mostly sunny
30
55
B
Tue0%
Sunny Sunny
31
57
A
Wed0%
Sunny Sunny
32
60
A
Thu0%
Mostly sunny Mostly sunny
36
62
A
Fri0%
Mostly sunny Mostly sunny
38
63
B
Letters show how sure the forecast is: A, models agree; B, some spread; C, check back. Sample data.
THIS WEEK IN 1993 · NOV. 16, 1993

79°, the hottest this week of the year has been since 1891.

2

What Plainsboro stands on

Plainsboro’s center stands about 90 ft above sea level. Within three miles the land runs from 50 ft to 170 ft, a difference of 120 ft: gently rolling country. The highest named summit within 15 miles is Sourland Mountain, about 640 ft, 11 miles northwest.

Plainsboro, northwest to southeast Plainsboro90 ftMillstone Riverabout 40 ft ← NWSE → 24 miles through the town center; vertical exaggeration about 71×. Colors: rock at the surface.
Elevation, center90 ft
Within 3 miles50 to 170 ft
Lie of the landGently rolling (120 ft of relief)
High point nearbySourland Mountain, 640 ft, 11 mi northwest
5

Plainsboro’s year

Plainsboro has a hot-summer humid continental climate. Summer afternoons average 87° in July; winter nights fall to about 21° in January. A normal year brings about 24 inches of snow; with the rain, that comes to about 48 inches of water.

JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC 12 47.5 in
July, average87° / 63° · high / low, the warmest month
January, average40° / 21° · high / low, the coldest month
Rain and melted snow47.5 in · wettest months: July and June
Snow a year23.7 in · snowiest: February
Hottest on record105°F · July 9, 1936
Coldest on record−16°F · January 28, 1935
Wettest day on record7.89 in · August 28, 2011
Snowiest day on record17.0 in · February 12, 1983
90° days a year26 · very few reach 100°
Nights at or below 32°114 · and 15 days that stay below freezing
Climate typeHot-summer humid continental · Köppen Dfa
1Freeze season · from the first fall freeze, about Oct. 18, to the last in spring, about April 23 (median dates)
2Lows below freezing · Nov. 17 to March 26; normal lows fall below 32°
NOVEMBER 14 IN THE RECORD

On November 14 Plainsboro normally reaches 56° and falls to 33°. The record high is 72°, in 1959; the record low 15°, in 2019. The most rain on this date, 1.89 in, fell in 1972.

Normals 1991–2020 and records since 1891 at Hightstown 2 W, 5 miles south-southeast. NOAA, through RCC-ACIS.
3

Where the rain goes

≈ 45 mito the AtlanticDevils Brook → Millstone → Raritan

A raindrop that lands in Plainsboro reaches New York Harbor and the Atlantic Ocean by way of Devils Brook, the Millstone and the Raritan: about 45 river miles.