Climate · Stillwater

Stillwater, NJ climate

Stillwater has chilly, snowy winters and pleasant summers. A typical July afternoon reaches 84°, a January night drops to 18°, and about 39 inches of snow falls in a normal winter.

NOAA 1991-2020 climate normals Updated once a decade
July high
84°
90th coolest of 941 New Jersey towns
January low
18°
18th coldest of 941 New Jersey towns
Rain + melted snow
48 in
442nd driest of 941 New Jersey towns
Snow a winter
39 in
5th snowiest of 898 New Jersey towns
A normal year

What a year in Stillwater feels like

Winter

39° / 20°
Typical high / low · 10 days with an inch or more of snow

Spring

60° / 36°
Typical high / low · Last frost around Apr 24

Summer

82° / 58°
Typical high / low · 12 days reach 90° in a normal year

Fall

63° / 41°
Typical high / low · First frost around Oct 16
Best months to be outsideMayJunJulAugSepOctHighs of 62–84° and lows of 40° or more
Month by month

Stillwater weather by month

Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.

MonthHighLowRain + meltSnowWet daysSnow on ground30-yr range
January36°18°3.3" 11.6"1117 18° – 35°
February39°20°2.7" 9.9"915 16° – 36°
March48°27°3.8" 6.3"119 30° – 47°
April61°36°3.8" 1.2"120 44° – 53°
May71°46°3.9" 0130 54° – 64°
June79°55°4.6" 0110 64° – 71°
July84°61°4.6" 0120 68° – 76°
August82°59°4.6" 0120 66° – 74°
September75°52°4.5" 0100 60° – 68°
October63°40°4.5" 0.3"110 47° – 59°
November52°31°3.3" 1.4"91 37° – 46°
December41°24°4.0" 8.0"1110 25° – 43°
Year61°39°47.5"38.7"13252

“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.

Rain & snow

Rain and snow in Stillwater

Stillwater gets 48 inches of rain and melted snow a year. June is the wettest month and February the driest. Rain or snow falls on about 132 days a year. Snow covers the ground about 52 days of the year.

48 in
Rain + melted snow a year
More rain than 79% of U.S. towns
39 in
Snow in a normal winter
More snow than 68% of U.S. towns
52 days
With 1"+ of snow on the ground
More than 67% of U.S. towns

Rain + melted snow by month

Inches of water
4.6"

Snowfall by month

Inches of snow
12"
Frost & the growing season

About 176 frost-free days a year

In half of years the last 32° night comes by April 24 and the first one by October 16. That leaves about 176 frost-free days for gardens, shorter than 53% of U.S. towns.

142
nights at or below 32° in a normal year
4
nights below 0° in a normal year
12
days that reach 90° in a normal year

Freezing nights by month

Average nights at or below 32°

90° days by month

Average days at 90° or more
Heating & cooling

Heating and cooling a home in Stillwater

Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Stillwater, 89% of that work is heating and 11% is cooling, so the furnace matters far more than the air conditioner.

89%heating
5,978 heating degree daysMore heating than 55% of U.S. towns
705 cooling degree daysLess cooling than 60% of U.S. towns

Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.

Around Stillwater

Stillwater and its neighbors

Stillwater borders 5 towns with climate data. January nights across them vary by 1.0°. Walpack has the coldest January nights (17°) and Hampton the hottest July afternoons (84°). Stillwater’s January low is 18° and its July high 84°.

Lafayette: January low 18°, July high 84°Andover: January low 18°, July high 84°Frankford: January low 18°, July high 84°Newton: January low 18°, July high 83°Green: January low 18°, July high 84°Lehman: January low 17°, July high 82°Middle Smithfield: January low 17°, July high 82°Delaware: January low 17°, July high 81°Sandyston: January low 17°, July high 84°Smithfield: January low 18°, July high 84°Blairstown: January low 18°, July high 84°Delaware Water Gap: January low 18°, July high 84°Knowlton: January low 19°, July high 84°Upper Mount Bethel: January low 19°, July high 84°Allamuchy: January low 18°, July high 84°Hope: January low 19°, July high 84°Independence: January low 19°, July high 84°Hampton: January low 18°, July high 84°Fredon: January low 18°, July high 83°Walpack: January low 17°, July high 82°Hardwick: January low 18°, July high 82°Frelinghuysen: January low 18°, July high 84°Stillwater: January low 18°, July high 84° StillwaterHamptonFredonWalpackHardwickFrelinghuysen
ColderMilder17° to 19°
Walpack17.2° −0.8°
Hampton17.8° −0.2°
Stillwater18.0°
Hardwick18.0° same
Fredon18.2° +0.2°
Frelinghuysen18.2° +0.2°

Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.

Compared with other towns

How Stillwater compares

Summer heat84° July high
Cooler than 59% of U.S. towns90th coolest of 941 New Jersey towns
Winter cold18° January low
Colder than 56% of U.S. towns18th coldest of 941 New Jersey towns
Precipitation48" a year
Wetter than 79% of U.S. towns442nd driest of 941 New Jersey towns
Snow39" a winter
Snowier than 68% of U.S. towns5th snowiest of 898 New Jersey towns
Growing season176 frost-free days
Shorter than 53% of U.S. towns202nd shortest of 941 New Jersey towns

Compared with every U.S. town and city on TownTapestry, each counted once.

Then and now

Warmer than it used to be

+2.0°1991–2020 average vs. the 20th century (1901–2000)

The last 30 years in Stillwater averaged 2.0° warmer than the 1900s. The biggest change is in December (+3.7°). The shift is larger than in 93% of U.S. towns.

❄️ Winter+3.1° now 30°, was 26°
🌷 Spring+1.6° now 48°, was 47°
☀️ Summer+1.4° now 70°, was 69°
🍂 Fall+1.7° now 52°, was 50°

Change by month1991–2020 average minus 1901–2000 average, at Stillwater’s spot on NOAA’s grid

Year to year

How much a month can swing

A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 16° to 36°. June is the most reliable, staying within 7°.

Coldest to warmest month in 30 yearsNormal
Questions

Common questions about Stillwater’s climate

What is the coldest month in Stillwater?

January, with a typical high of 36° and a low of 18°.

What is the hottest month in Stillwater?

July, with a typical high of 84° and a low of 61°. About 12 days a year reach 90°.

How much snow does Stillwater get?

About 39 inches in a normal winter, most of it in January.

When is the first frost in Stillwater?

In half of years the first 32° night comes by October 16, and the last spring frost by April 24.

What is the rainiest month in Stillwater?

June, with 4.6 inches of rain and melted snow. The year totals 48 inches.

Temperatures and rainfall come from NOAA’s gridded climate normals for Stillwater itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Sussex 3 Wnw, NJ (15 mi, snow) and Newton, NJ (6 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.

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