Chantilly weather in January

In January, Chantilly sees average daytime highs of 42°F and overnight lows near 28°F, with 3.0 in of precipitation across 8.6 wet days and about 9.6 hours of daylight. It is the 12th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 42°F through the month. The sky is clear or mostly clear about 31% of the time in January, and the air most often feels dry.

Daylight stretches from about 9 h 18 min at the start of January to 10 hours by month's end. Set against the rest of the year, January is Chantilly's 6th-clearest and 2nd-windiest month. For the whole year in context, see Chantilly's year-round climate.

Daytime high
42°
12th warmest
Overnight low
28°
1st coldest
Precipitation
3.0 in
8.6 wet days
Daylight
9 h 36 min
7:32 AM – 5:06 PM
Cloud cover
59%
6th clearest
Wind
7 mph
2nd windiest
Solar energy
2.24 kWh/m²
Travel score
0.3
out of 10

Chantilly is unincorporated community located in Northern Virginia, United States.

Density
733/km²
people per km²

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

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 42°F through the month.

A typical January day in Chantilly reaches about 42°F in the afternoon and slips back to 28°F overnight — a 15°F spread between the day's warmth and the night's chill. On most days the high lands between 29°F and 56°F. Set against its neighbours, January runs about 4°F cooler than December and about 3°F cooler than February.

20°30°40°50°60°151015202531
Avg high (°F)Avg low (°F)
14430
24429
34429
44329
54329
64329
74329
84329
94329
104329
114228
124228
134228
144228
154228
164227
174227
184127
194127
204127
214127
224127
234126
244126
254126
264226
274226
284227
294227
304227
314227

How January really feels in Chantilly

Once humidity and wind are folded in, January 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 January is cold — wind chill drags the overnight "feels like" below the raw low.

Chantilly weather by month

How January compares with the rest of the year at a glance. January is the 12th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan42° / 28°3.08.639.60.3
Feb45° / 29°2.88.1310.51.1
Mar54° / 36°3.810211.73.3
Apr66° / 46°3.410.30.1135.8
May74° / 56°3.811.3014.16.5
Jun83° / 65°3.411.2014.75.5
Jul88° / 69°3.911.8014.44.4
Aug85° / 68°3.310.4013.55.1
Sep78° / 60°4.49.5012.36.7
Oct67° / 49°3.47.80116.5
Nov55° / 38°3.07.60.39.93.9
Dec46° / 32°3.59.12.19.31.3

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 31% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 15% of January, with mostly cloudy or overcast conditions the remaining 54%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14852
24753
34753
44852
54753
64753
74654
84654
94654
104753
114753
124654
134654
144654
154654
164555
174555
184555
194456
204456
214555
224555
234654
244753
254654
264654
274852
284852
294852
304852
314951

Chance of precipitation in January

Any precipitationSnow

Chantilly gets around 3.0 in of rain and snow over 8.6 wet days in January. 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 31% on the wettest days, and about 3 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
1287
2287
3297
4298
5308
6308
7308
8318
9319
10319
11319
12319
133110
143010
153010
162910
172910
182810
192810
202711
212711
222611
232611
242511
252511
262511
272512
282512
292512
302511
312511

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January 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 (%)Humid (%)
19811
29811
39811
49811
59811
69811
79811
89811
99811
109811
119811
129811
139811
149910
159910
169910
179910
189910
199910
209910
219910
229910
239910
2410000
2510000
2610000
2710000
2810000
2910000
3010000
3110000

Wind in January

Winds average 7 mph in January.

Across January, 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 January

DaylightNight

Daylight runs from about 9 h 18 min at the start of January to 10 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over January. Sunrise moves from 7:33 AM to 7:24 AM, and sunset from 4:52 PM to 5:22 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.37:334:52
29.37:344:53
39.37:344:54
49.37:344:55
59.47:344:56
69.47:344:56
79.47:344:57
89.47:344:58
99.47:344:59
109.47:345:00
119.57:335:01
129.57:335:02
139.57:335:03
149.57:335:04
159.57:335:05
169.67:325:06
179.67:325:07
189.67:325:08
199.67:315:09
209.67:315:10
219.77:305:11
229.77:305:12
239.77:295:13
249.87:295:14
259.87:285:15
269.87:285:16
279.87:275:17
289.97:265:19
299.97:265:20
309.97:255:21
3110.07:245:22

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 2.24 kWh/m².

For context, solar energy here swings from a low near 1.95 kWh/m² to a high of 6.15 kWh/m² in June across the year — January's 2.24 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.0Moderate
22.0Moderate
32.0Moderate
42.0Moderate
52.0Moderate
62.0Moderate
72.0Moderate
82.1Moderate
92.1Moderate
102.1Moderate
112.1Moderate
122.1Moderate
132.1Moderate
142.2Moderate
152.2Moderate
162.2Moderate
172.2Moderate
182.3Moderate
192.3Moderate
202.3Moderate
212.4Moderate
222.4Moderate
232.4Moderate
242.5Moderate
252.5Moderate
262.5Moderate
272.5Moderate
282.6Moderate
292.6Moderate
302.6Moderate
312.7Moderate
Planning a trip in January

Is January a good time to visit Chantilly?

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

0.3
Sightseeing
12th-best month of the year
0.0
Beach & pool
10th-best month of the year

January is a weaker month for outdoor sightseeing in Chantilly.

What to pack for Chantilly in January

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

In January, Chantilly sees daytime highs around 42°F and nights near 28°F. Pack a warm layer and a heavy coat. Worth having: rain gear. About 9 days see rain.

a warm layera heavy coatrain gear

UV index in Chantilly in January

LowModerateHighVery highExtreme

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

Under clear skies, the midday UV index in Chantilly 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 Chantilly in January

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Chantilly 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 Chantilly?

Chantilly sits at 38.9°N, 77.4°W, 322 ft above sea level, in United States. The nearest listed city is Oak Hill, 2.5 mi away.

Topography around Chantilly

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

Within 2 miles, the terrain around Chantilly has only modest variations in elevation — a maximum elevation change of 180 ft around an average of 328 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 768 ft; within 50 miles, large variations in elevation — a maximum elevation change of 3,609 ft.

The land around Chantilly is covered by trees (51%) and artificial surfaces (34%) within 2 miles, trees (67%) within 10 miles, and trees (66%) within 50 miles.

2 miles
180 ft
10 miles
768 ft
50 miles
3,609 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
January weather nearby: Oak Hill 2.5 mi · Centreville 3.7 mi · South Riding 4.3 mi · Herndon 5.6 mi · Reston 6.8 mi · Oakton 6.8 mi · Fairfax 7.5 mi · Sterling 7.5 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 Chantilly (38.8943°, -77.4311°, elevation 322 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).