Chantilly weather in October

In October, Chantilly sees average daytime highs of 67°F and overnight lows near 49°F, with 3.4 in of rain across 7.8 wet days and about 11 hours of daylight. It is the 6th-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 72°F in the first days to 62°F by the end. The sky is clear or mostly clear about 41% of the time in October, and the air most often feels dry.

Daylight stretches from about 11 h 36 min at the start of October to 10 h 24 min by month's end. Set against the rest of the year, October is Chantilly's 1st-clearest and 7th-windiest month. For the whole year in context, see Chantilly's year-round climate.

Daytime high
67°
6th warmest
Overnight low
49°
7th coldest
Rainfall
3.4 in
7.8 wet days
Daylight
11 hours
6:26 AM – 5:24 PM
Cloud cover
51%
1st clearest
Wind
6 mph
7th windiest
Solar energy
3.35 kWh/m²
Travel score
6.5
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 October

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 72°F in the first days to 62°F by the end.

A typical October day in Chantilly reaches about 67°F in the afternoon and slips back to 49°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 56°F and 78°F. Set against its neighbours, October runs about 12°F cooler than September and about 12°F warmer than November.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
17355
27354
37254
47253
57153
67153
77152
87052
97051
106951
116951
126950
136850
146849
156749
166748
176748
186648
196647
206547
216547
226546
236446
246446
256345
266345
276345
286244
296244
306244
316143

How October really feels in Chantilly

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

October sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Chantilly weather by month

How October compares with the rest of the year at a glance. October is the 6th-warmest and 8th-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 October

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 41% of the time in October, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 15% of October, with mostly cloudy or overcast conditions the remaining 44%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15446
25545
35644
45644
55743
65743
75644
85644
95644
105644
115644
125644
135644
145644
155644
165644
175644
185644
195644
205644
215644
225644
235644
245644
255545
265545
275644
285644
295545
305545
315446

Chance of precipitation in October

Any precipitation

Chantilly gets around 3.4 in of rain over 7.8 wet days in October. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 26% and peaks near 29% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
129
229
328
428
527
626
726
826
925
1025
1126
1226
1326
1426
1526
1626
1726
1826
1926
2026
2126
2226
2326
2426
2525
2625
2725
2825
2924
3024
3124

Humidity in October

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, October lands in the dry band about 76% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
157171691
258161691
360161581
461161481
562161471
665151361
766151261
867151251
969151141
1070151041
117215931
127315831
137315831
147515721
157615621
167715521
178014510
188114410
198213410
208213410
218412310
228412310
238511310
248511310
258610310
268710210
278710210
28899200
29899200
30899200
31908200

Wind in October

Winds average 6 mph in October.

Across October, 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
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in October

DaylightNight

Daylight runs from about 11 h 36 min at the start of October to 10 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 72 minutes over October. Sunrise moves from 6:11 AM to 6:42 AM, and sunset from 5:47 PM to 5:05 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.66:115:47
211.66:125:45
311.56:135:43
411.56:145:42
511.46:155:40
611.46:165:39
711.36:175:37
811.36:185:36
911.36:195:34
1011.26:205:33
1111.26:215:31
1211.16:225:30
1311.16:235:28
1411.06:245:27
1511.06:255:25
1611.06:265:24
1710.96:275:22
1810.96:285:21
1910.86:295:20
2010.86:305:18
2110.86:315:17
2210.76:325:15
2310.76:335:14
2410.66:345:13
2510.66:355:12
2610.66:365:10
2710.56:385:09
2810.56:395:08
2910.56:405:07
3010.46:415:06
3110.46:425:05

Solar energy in October

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in October, about 3.35 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 — October's 3.35 kWh/m² falls in the middle.

01234151015202531
Solar energy (kWh/m²)Level
13.8Moderate
23.8Moderate
33.7Moderate
43.7Moderate
53.7Moderate
63.6Moderate
73.6Moderate
83.6Moderate
93.6Moderate
103.5Moderate
113.5Moderate
123.5Moderate
133.4Moderate
143.4Moderate
153.4Moderate
163.3Moderate
173.3Moderate
183.3Moderate
193.2Moderate
203.2Moderate
213.2Moderate
223.1Moderate
233.1Moderate
243.1Moderate
253.0Moderate
263.0Moderate
273.0Moderate
282.9Moderate
292.9Moderate
302.9Moderate
312.9Moderate
Planning a trip in October

Is October a good time to visit Chantilly?

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

6.5
Sightseeing
2nd-best month of the year
3.1
Beach & pool
6th-best month of the year

October is a reasonable time to visit Chantilly for sightseeing.

What to pack for Chantilly in October

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

In October, Chantilly sees daytime highs around 67°F and nights near 49°F. Little to plan around — just the basics. About 8 days see rain.

UV index in Chantilly in October

LowModerateHighVery highExtreme

Clear-sky midday UV in October peaks around 4 — enough to warrant sun protection. 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 October

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where October 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
October 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).