Montclair weather in August

In August, Montclair sees average daytime highs of 85°F and overnight lows near 70°F, with 3.5 in of rain across 10.2 wet days and about 13.5 hours of daylight. It is the 2nd-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 87°F in the first days to 84°F by the end. The sky is clear or mostly clear about 30% of the time in August, and the air most often feels muggy.

Daylight stretches from about 14 hours at the start of August to 12 h 54 min by month's end. Set against the rest of the year, August is Montclair's 4th-clearest and 12th-windiest month. For the whole year in context, see Montclair's year-round climate.

Daytime high
85°
2nd warmest
Overnight low
70°
11th coldest
Rainfall
3.5 in
10.2 wet days
Daylight
13 h 30 min
5:28 AM – 6:59 PM
Cloud cover
57%
4th clearest
Wind
5 mph
12th windiest
Solar energy
5.36 kWh/m²
Travel score
5.1
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 August

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 87°F in the first days to 84°F by the end.

A typical August day in Montclair reaches about 85°F in the afternoon and slips back to 70°F overnight — a 15°F spread between the day's warmth and the night's chill. On most days the high lands between 78°F and 93°F. Set against its neighbours, August runs about 2°F cooler than July and about 7°F warmer than September.

60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18772
28772
38772
48771
58771
68771
78771
88671
98671
108671
118671
128671
138671
148671
158671
168670
178570
188570
198570
208570
218570
228570
238569
248569
258569
268469
278469
288469
298469
308468
318468

How August really feels in Montclair

Once humidity and wind are folded in, August averages 3 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
3
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

The story in August is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Montclair weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 4th-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 August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 23% of August, with mostly cloudy or overcast conditions the remaining 47%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15149
25149
35248
45347
55347
65347
75347
85347
95347
105446
115446
125347
135446
145446
155347
165446
175446
185545
195446
205446
215446
225446
235446
245347
255347
265446
275347
285347
295347
305347
315347

Chance of precipitation in August

Any precipitation

Montclair gets around 3.5 in of rain over 10.2 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 34% and peaks near 38% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
138
237
337
436
536
636
736
836
936
1037
1137
1237
1337
1437
1537
1636
1736
1835
1934
2033
2133
2232
2331
2431
2530
2630
2730
2830
2930
3031
3131

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the muggy band about 34% of days. Sticky, muggy-or-worse air turns up on roughly 64% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1281836360
2281836350
3281836350
4391836341
5391835341
6391935341
7391935341
8391935331
9491934331
10491934331
11491934321
12492035321
13492035321
14492035311
15492135311
16492135301
17492235291
184102235290
194102335280
204102335280
214102335270
224112435260
234112435260
244112534260
254122533250
264122633250
275132632241
285132731241
295142730241
306142729231
316152728231

Wind in August

Winds average 5 mph in August, the calmest month.

Across August, daily wind ranges from about 5 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 hours at the start of August to 12 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over August. Sunrise moves from 5:14 AM to 5:42 AM, and sunset from 7:16 PM to 6:37 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.05:147:16
214.05:157:15
314.05:167:14
413.95:177:13
513.95:187:12
613.95:197:11
713.85:207:10
813.85:217:09
913.85:227:08
1013.75:237:07
1113.75:237:05
1213.75:247:04
1313.65:257:03
1413.65:267:02
1513.65:277:00
1613.55:286:59
1713.55:296:58
1813.45:306:56
1913.45:316:55
2013.45:326:53
2113.35:336:52
2213.35:346:51
2313.25:346:49
2413.25:356:48
2513.25:366:46
2613.15:376:45
2713.15:386:43
2813.05:396:42
2913.05:406:40
3013.05:416:39
3112.95:426:37

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.36 kWh/m².

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 — August's 5.36 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.6Bright
25.6Bright
35.6Bright
45.6Bright
55.6Bright
65.5Bright
75.5Bright
85.5Bright
95.5Bright
105.5Bright
115.5Bright
125.4Bright
135.4Bright
145.4Bright
155.4Bright
165.3Bright
175.3Bright
185.3Bright
195.3Bright
205.3Bright
215.2Bright
225.2Bright
235.2Bright
245.1Bright
255.1Bright
265.1Bright
275.0Bright
285.0Bright
295.0Bright
304.9Bright
314.9Bright
Planning a trip in August

Hazard calendar for Montclair

In seasonPeak

In August, Montclair sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

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 August a good time to visit Montclair?

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

5.1
Sightseeing
6th-best month of the year
6.8
Beach & pool
1st-best month of the year

August is a reasonable time to visit Montclair for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Montclair in August

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

In August, Montclair sees daytime highs around 85°F and nights near 70°F. Pack light clothes. Worth having: rain gear and sun protection. About 10 days see rain.

light clothesrain gearsun protection

UV index in Montclair in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 7 — enough to warrant sun protection. 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 August

GoodModeratePoorUnhealthyVery unhealthy

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