Manassas weather in December

In December, Manassas sees average daytime highs of 47°F and overnight lows near 32°F, with 3.4 in of precipitation across 8.8 wet days and about 9.3 hours of daylight. It is the 10th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 50°F in the first days to 45°F by the end. The sky is clear or mostly clear about 35% 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 Manassas's 4th-clearest and 6th-windiest month. For the whole year in context, see Manassas's year-round climate.

Daytime high
47°
10th warmest
Overnight low
32°
3rd coldest
Precipitation
3.4 in
8.8 wet days
Daylight
9 h 18 min
7:27 AM – 4:45 PM
Cloud cover
58%
4th clearest
Wind
7 mph
6th windiest
Solar energy
1.99 kWh/m²
Travel score
1.6
out of 10

Manassas is independent city in Virginia, United States.

Density
1,623/km²
people per km²
Founded
1975

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 50°F in the first days to 45°F by the end.

A typical December day in Manassas reaches about 47°F in the afternoon and slips back to 32°F overnight — a 15°F spread between the day's warmth and the night's chill. On most days the high lands between 35°F and 60°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)
15135
25135
35035
45035
55034
64934
74934
84834
94833
104833
114733
124733
134733
144732
154732
164632
174632
184632
194632
204631
214631
224631
234631
244631
254631
264631
274531
284531
294531
304531
314531

How December really feels in Manassas

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.

Manassas weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan43° / 29°3.08.62.89.60.6
Feb47° / 30°2.88.32.510.51.4
Mar55° / 37°3.810.51.711.73.6
Apr67° / 47°3.4100136.0
May75° / 56°3.711.2014.16.5
Jun84° / 65°3.411.1014.75.3
Jul88° / 70°3.711.8014.44.2
Aug86° / 69°3.310013.55.0
Sep79° / 61°4.49.1012.36.7
Oct68° / 49°3.37.60116.7
Nov56° / 39°2.97.60.29.94.2
Dec47° / 32°3.48.81.89.31.6

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 13% of December, with mostly cloudy or overcast conditions the remaining 52%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15050
24951
34951
44852
54852
64852
74753
84753
94753
104654
114654
124753
134753
144753
154852
164852
174852
184753
194852
204852
214852
224951
234951
244951
255050
264951
274951
285050
294951
304951
315050

Chance of precipitation in December

Any precipitationSnow

Manassas 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 29% and peaks near 31% on the wettest days, and about 2 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
1303
2304
3304
4315
5315
6315
7316
8316
9316
10317
11317
12317
13307
14307
15307
16296
17296
18296
19286
20286
21276
22276
23266
24266
25265
26265
27265
28265
29265
30266
31276

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 (%)
19730
29730
39730
49730
59730
69820
79820
89820
99820
109820
119820
129910
139910
149910
159910
169910
179910
189910
199811
209811
219811
229811
239811
249811
259811
269901
279901
289901
299901
309901
319901

Wind in December

Winds average 7 mph in December.

Across December, daily wind ranges from about 6 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
106calm
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 7:15 AM to 7:33 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)
19.57:154:44
29.57:164:44
39.57:174:44
49.47:184:44
59.47:194:44
69.47:204:44
79.47:204:44
89.47:214:44
99.47:224:44
109.47:234:44
119.37:244:44
129.37:244:44
139.37:254:44
149.37:264:45
159.37:264:45
169.37:274:45
179.37:284:45
189.37:284:46
199.37:294:46
209.37:294:47
219.37:304:47
229.37:304:47
239.37:314:48
249.37:314:48
259.37:324:49
269.37:324:50
279.37:324:50
289.37:334:51
299.37:334:51
309.37:334:52
319.37:334:53

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.99 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.99 kWh/m² to a high of 6.15 kWh/m² in June across the year — December's 1.99 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.1Moderate
22.1Moderate
32.1Moderate
42.1Moderate
52.0Moderate
62.0Moderate
72.0Moderate
82.0Moderate
92.0Dim
102.0Dim
112.0Dim
121.9Dim
131.9Dim
141.9Dim
151.9Dim
161.9Dim
171.9Dim
181.9Dim
191.9Dim
201.9Dim
212.0Dim
222.0Dim
232.0Dim
242.0Dim
252.0Dim
262.0Dim
272.0Moderate
282.0Moderate
292.0Moderate
302.0Moderate
312.0Moderate
Planning a trip in December

Is December a good time to visit Manassas?

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

1.6
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 Manassas.

What to pack for Manassas in December

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

In December, Manassas sees daytime highs around 47°F and nights near 32°F. Pack a warm layer. Worth having: rain gear. About 9 days see rain.

a warm layerrain gear

UV index in Manassas 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 Manassas 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
Aug7Very high
Sep6High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Manassas 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 Manassas is worst in July — around 17 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (November, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1317 µg/m³Nov 129 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb12Moderate
Mar13Moderate
Apr13Moderate
May15Moderate
Jun16Moderate
Jul17Moderate
Aug15Moderate
Sep12Moderate
Oct9Good
Nov9Good
Dec10Good
Location & terrain

Where is Manassas?

Manassas sits at 38.8°N, 77.5°W, 305 ft above sea level, in United States. The nearest listed city is Manassas Park, 2.5 mi away.

Topography around Manassas

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

Within 2 miles, the terrain around Manassas has only modest variations in elevation — a maximum elevation change of 194 ft around an average of 272 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 768 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,157 ft.

The land around Manassas is covered by trees (54%) and artificial surfaces (32%) within 2 miles, trees (71%) within 10 miles, and trees (68%) within 50 miles.

2 miles
194 ft
10 miles
768 ft
50 miles
4,157 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Manassas Park 2.5 mi · Buckhall 2.5 mi · Sudley 3.1 mi · Linton Hall 5.6 mi · Centreville 6.8 mi · Chantilly 9.9 mi · Lake Ridge 11 mi · Fairfax 11 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 Manassas (38.751°, -77.4753°, elevation 305 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. 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).