Montclair weather in December

In December, Montclair sees average daytime highs of 48°F and overnight lows near 34°F, with 3.4 in of precipitation across 8.8 wet days and about 9.4 hours of daylight. It is the 10th-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 51°F in the first days to 46°F by the end. The sky is clear or mostly clear about 36% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 30 min at the start of December to 9 h 18 min by month's end. Set against the rest of the year, December is Montclair's 5th-clearest and 6th-windiest month. For the whole year in context, see Montclair's year-round climate.

Daytime high
48°
10th warmest
Overnight low
34°
3rd coldest
Precipitation
3.4 in
8.8 wet days
Daylight
9 h 18 min
7:26 AM – 4:45 PM
Cloud cover
57%
5th clearest
Wind
7 mph
6th windiest
Solar energy
2.01 kWh/m²
Travel score
1.9
out of 10

Montclair is census designated place in Prince William County, Virginia, United States.

Density
1,224/km²
people per km²

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 51°F in the first days to 46°F by the end.

A typical December day in Montclair reaches about 48°F in the afternoon and slips back to 34°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 36°F and 61°F. Set against its neighbours, December runs about 9°F cooler than November and about 4°F warmer than January.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
15237
25237
35137
45137
55137
65036
75036
84936
94935
104935
114935
124835
134835
144834
154834
164734
174734
184734
194734
204733
214733
224733
234733
244733
254633
264633
274633
284633
294633
304632
314632

How December really feels in Montclair

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 30 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
30
wind chill below the day's low

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

Montclair weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan44° / 30°3.18.52.79.60.9
Feb47° / 31°2.88.22.310.51.6
Mar56° / 39°3.910.21.611.73.8
Apr67° / 49°3.39.40136.2
May75° / 58°3.510.9014.16.6
Jun84° / 67°3.511.2014.65.5
Jul88° / 72°3.711.7014.44.3
Aug85° / 70°3.510.2013.55.1
Sep79° / 63°4.29.5012.36.7
Oct68° / 52°3.47.80116.7
Nov57° / 41°2.97.30.19.94.4
Dec48° / 34°3.48.81.49.41.9

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 14% of December, with mostly cloudy or overcast conditions the remaining 51%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15248
25149
35149
45149
55050
65050
74951
84852
94852
104852
114852
124852
134852
144852
154852
164852
174951
184951
194951
204951
214951
225050
235050
245050
255050
265050
275050
285050
295050
305050
315050

Chance of precipitation in December

Any precipitationSnow

Montclair gets around 3.4 in of rain and snow over 8.8 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 28% and peaks near 30% on the wettest days, and about 1 day brings snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
1293
2293
3304
4304
5304
6304
7305
8305
9305
10305
11305
12305
13305
14305
15295
16295
17294
18294
19284
20284
21284
22274
23274
24274
25264
26264
27264
28264
29265
30265
31275

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 98% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19640
29640
39640
49730
59730
69730
79730
89820
99820
109820
119820
129820
139820
149910
159910
169910
179910
189910
199811
209811
219811
229811
239811
249811
259811
269811
279811
289811
299811
309811
319811

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
317calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 30 min at the start of December to 9 h 18 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 7:14 AM to 7:32 AM, and sunset from 4:44 PM to 4:53 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.57:144:44
29.57:154:44
39.57:164:44
49.47:174:44
59.47:184:44
69.47:194:44
79.47:194:44
89.47:204:44
99.47:214:44
109.47:224:44
119.47:234:44
129.37:234:44
139.37:244:44
149.37:254:44
159.37:254:45
169.37:264:45
179.37:274:45
189.37:274:46
199.37:284:46
209.37:284:46
219.37:294:47
229.37:294:47
239.37:304:48
249.37:304:48
259.37:314:49
269.37:314:49
279.37:314:50
289.37:324:51
299.37:324:51
309.37:324:52
319.37:324:53

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.01 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.01 kWh/m² to a high of 6.15 kWh/m² in June across the year — December's 2.01 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.1Moderate
22.1Moderate
32.1Moderate
42.1Moderate
52.1Moderate
62.1Moderate
72.0Moderate
82.0Moderate
92.0Moderate
102.0Dim
112.0Dim
122.0Dim
132.0Dim
142.0Dim
152.0Dim
161.9Dim
172.0Dim
182.0Dim
192.0Dim
202.0Dim
212.0Dim
222.0Dim
232.0Dim
242.0Moderate
252.0Moderate
262.0Moderate
272.0Moderate
282.0Moderate
292.0Moderate
302.0Moderate
312.0Moderate
Planning a trip in December

Hazard calendar for Montclair

In seasonPeak

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

Montclair 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 Montclair?

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

1.9
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 Montclair.

What to pack for Montclair in December

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

In December, Montclair sees daytime highs around 48°F and nights near 34°F. Pack a warm layer. Worth having: rain gear. About 9 days see rain.

a warm layerrain gear

UV index in Montclair in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Montclair peaks around July 11 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 11UV 9Dec 19UV 2
UV index (midday)Level
Jan2Moderate
Feb3Moderate
Mar5High
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug7High
Sep6High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Montclair 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 Montclair 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 187 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar12Good
Apr13Moderate
May14Moderate
Jun15Moderate
Jul16Moderate
Aug14Moderate
Sep11Good
Oct8Good
Nov7Good
Dec8Good
Location & terrain

Where is Montclair?

Montclair sits at 38.6°N, 77.3°W, 125 ft above sea level, in United States. The nearest listed city is Dale City, 2.5 mi away.

Topography around Montclair

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

Within 2 miles, the terrain around Montclair has only modest variations in elevation — a maximum elevation change of 302 ft around an average of 230 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 577 ft; within 50 miles, large variations in elevation — a maximum elevation change of 3,514 ft.

The land around Montclair is covered by trees (78%) within 2 miles, trees (74%) within 10 miles, and trees (69%) within 50 miles.

2 miles
302 ft
10 miles
577 ft
50 miles
3,514 ft
treesgrasslandcroplandartificial surfaceswaterwetland
December weather nearby: Dale City 2.5 mi · Cherry Hill 5.0 mi · Lake Ridge 5.6 mi · Lorton 8.7 mi · Buckhall 9.9 mi · Manassas 12 mi · West Springfield 13 mi · Burke 13 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 Montclair (38.611°, -77.3397°, elevation 125 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).