Hopatcong Hills weather in December

In December, Hopatcong Hills sees average daytime highs of 40°F and overnight lows near 28°F, with 4.0 in of precipitation across 10 wet days and about 9.1 hours of daylight. It is the 10th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 44°F in the first days to 38°F by the end. The sky is clear or mostly clear about 26% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 18 min at the start of December to 9 h 06 min by month's end. Set against the rest of the year, December is Hopatcong Hills's 9th-clearest and 4th-windiest month. For the whole year in context, see Hopatcong Hills's year-round climate.

Daytime high
40°
10th warmest
Overnight low
28°
3rd coldest
Precipitation
4.0 in
10 wet days
Daylight
9 h 06 min
7:23 AM – 4:27 PM
Cloud cover
64%
9th clearest
Wind
7 mph
4th windiest
Solar energy
1.71 kWh/m²
Travel score
0.2
out of 10

Hopatcong Hills is human settlement in Sussex County, New Jersey, United States of America.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 44°F in the first days to 38°F by the end.

A typical December day in Hopatcong Hills reaches about 40°F in the afternoon and slips back to 28°F overnight — a 13°F spread between the day's warmth and the night's chill. On most days the high lands between 29°F and 53°F. Set against its neighbours, December runs about 10°F cooler than November and about 5°F warmer than January.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
14531
24531
34431
44431
54330
64330
74229
84229
94229
104129
114128
124128
134028
144028
154028
164027
174027
184027
194027
203927
213927
223926
233926
243926
253926
263826
273826
283826
293825
303825
313825

How December really feels in Hopatcong Hills

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 31 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
31
wind chill below the day's low

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Hopatcong Hills weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan36° / 22°3.59.55.69.40.0
Feb39° / 23°3.08.84.610.40.0
Mar47° / 31°4.110.94.111.71.5
Apr59° / 41°3.710.80.713.14.4
May69° / 51°3.711.7014.36.1
Jun78° / 60°3.911.3014.96.4
Jul83° / 65°3.710.7014.65.7
Aug81° / 64°3.610.5013.66.3
Sep74° / 56°4.29.6012.36.9
Oct62° / 45°4.090.210.95.4
Nov50° / 35°3.28.319.72.5
Dec40° / 28°4.01049.10.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 26% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 15% of December, with mostly cloudy or overcast conditions the remaining 59%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14258
24258
34159
44060
54159
64060
74060
83961
93961
103862
113862
123862
133961
143961
153961
164060
174159
184159
194159
204357
214357
224357
234456
244555
254555
264555
274456
284456
294456
304456
314456

Chance of precipitation in December

Any precipitationSnow

Hopatcong Hills gets around 4.0 in of rain and snow over 10 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 32% and peaks near 35% on the wettest days, and about 4 days bring snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1328
2329
33310
43311
53411
63412
73413
83513
93514
103514
113514
123414
133414
143414
153314
163314
173213
183213
193113
203112
213012
223012
233012
243012
253012
263012
273013
283013
293114
303114
313115

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1991
2991
3991
4991
5991
61000
71000
81000
91000
101000
111000
121000
131000
141000
151000
161000
171000
18991
19991
20991
21991
22991
23991
24991
25991
26991
27991
28991
291000
301000
311000

Wind in December

Winds average 7 mph in December.

Across December, daily wind ranges from about 7 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 18 min at the start of December to 9 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:10 AM to 7:29 AM, and sunset from 4:27 PM to 4:35 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.37:104:27
29.37:114:26
39.27:124:26
49.27:134:26
59.27:144:26
69.27:154:26
79.27:164:26
89.27:174:26
99.17:174:26
109.17:184:26
119.17:194:26
129.17:204:26
139.17:214:26
149.17:214:27
159.17:224:27
169.17:234:27
179.17:234:27
189.17:244:28
199.17:244:28
209.17:254:28
219.17:264:29
229.17:264:29
239.17:264:30
249.17:274:30
259.17:274:31
269.17:284:31
279.17:284:32
289.17:284:33
299.17:294:33
309.17:294:34
319.17:294:35

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.71 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.71 kWh/m² to a high of 5.96 kWh/m² in June across the year — December's 1.71 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.8Dim
31.8Dim
41.8Dim
51.8Dim
61.7Dim
71.7Dim
81.7Dim
91.7Dim
101.7Dim
111.7Dim
121.7Dim
131.7Dim
141.7Dim
151.7Dim
161.7Dim
171.7Dim
181.7Dim
191.7Dim
201.7Dim
211.7Dim
221.7Dim
231.7Dim
241.7Dim
251.7Dim
261.7Dim
271.7Dim
281.7Dim
291.8Dim
301.8Dim
311.8Dim
Planning a trip in December

Hazard calendar for Hopatcong Hills

In seasonPeak

None of Hopatcong Hills's seasonal hazards are active in December. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Hopatcong Hills sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Hopatcong Hills?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

0.2
Sightseeing
10th-best month of the year
0.0
Beach & pool
10th-best month of the year

December is a weaker month for outdoor sightseeing in Hopatcong Hills.

What to pack for Hopatcong Hills in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Hopatcong Hills sees daytime highs around 40°F and nights near 28°F. Pack a warm layer and a heavy coat. Worth having: rain gear. About 10 days see rain.

a warm layera heavy coatrain gear

UV index in Hopatcong Hills in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Hopatcong Hills peaks around July 10 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 10UV 8Dec 22UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun8Very high
Jul8Very high
Aug6High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in Hopatcong Hills in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Hopatcong Hills is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (November, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1416 µg/m³Nov 157 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar12Good
Apr12Moderate
May15Moderate
Jun15Moderate
Jul16Moderate
Aug13Moderate
Sep11Good
Oct8Good
Nov7Good
Dec8Good
Location & terrain

Where is Hopatcong Hills?

Hopatcong Hills sits at 40.9°N, 74.7°W, 1,102 ft above sea level, in United States. The nearest listed city is Sparta, 6.2 mi away.

Topography around Hopatcong Hills

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Hopatcong Hills.

Within 2 miles, the terrain around Hopatcong Hills has only modest variations in elevation — a maximum elevation change of 531 ft around an average of 968 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 932 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,467 ft.

The land around Hopatcong Hills is covered by trees (73%) within 2 miles, trees (80%) within 10 miles, and trees (74%) within 50 miles.

2 miles
531 ft
10 miles
932 ft
50 miles
2,467 ft
treesgrasslandcroplandartificial surfaceswaterwetland
December weather nearby: Sparta 6.2 mi · Dover 6.8 mi · Randolph 8.1 mi · Denville 11 mi · Parsippany 14 mi · Morristown 14 mi · Basking Ridge 17 mi · Madison 19 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Hopatcong Hills (40.944°, -74.6707°, elevation 1,102 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).