Portsmouth weather in August

In August, Portsmouth sees average daytime highs of 85°F and overnight lows near 71°F, with 4.7 in of rain across 12.9 wet days and about 13.4 hours of daylight. It is the 2nd-warmest and 3rd-wettest month of the year here.

Day-to-day highs hold fairly steady near 85°F through the month. The sky is clear or mostly clear about 31% of the time in August, and the air most often feels oppressive.

Daylight stretches from about 13 h 54 min at the start of August to 12 h 54 min by month's end. Set against the rest of the year, August is Portsmouth's 8th-clearest and 12th-windiest month. For the whole year in context, see Portsmouth's year-round climate.

Daytime high
85°
2nd warmest
Overnight low
71°
11th coldest
Rainfall
4.7 in
12.9 wet days
Daylight
13 h 24 min
5:27 AM – 6:52 PM
Cloud cover
58%
8th clearest
Wind
6 mph
12th windiest
Solar energy
5.52 kWh/m²
Travel score
5.0
out of 10

Portsmouth is independent city in Virginia, United States.

Density
796/km²
people per km²
Founded
1752

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

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 85°F through the month.

A typical August day in Portsmouth reaches about 85°F in the afternoon and slips back to 71°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 78°F and 91°F. Set against its neighbours, August runs about 2°F cooler than July and about 5°F warmer than September.

60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18673
28673
38673
48672
58672
68672
78572
88572
98572
108572
118572
128572
138572
148572
158571
168571
178571
188571
198571
208571
218471
228471
238471
248471
258471
268470
278470
288470
298370
308370
318370

How August really feels in Portsmouth

Once humidity and wind are folded in, August averages 11 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
11
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.

Portsmouth weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan49° / 34°3.49.11.39.82.2
Feb52° / 35°3.091.110.62.8
Mar59° / 42°3.910.40.511.74.5
Apr68° / 51°3.39.7012.96.4
May75° / 59°3.710.9013.96.7
Jun83° / 68°4.111.7014.55.6
Jul87° / 73°5.215.1014.34.3
Aug85° / 71°4.712.9013.45.0
Sep80° / 66°4.711.1012.26.4
Oct71° / 55°3.77.90117.0
Nov61° / 45°3.48.50.1105.3
Dec53° / 38°3.59.30.59.53.2

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

Beyond those clear spells, partly cloudy skies cover about 19% of August, with mostly cloudy or overcast conditions the remaining 50%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14753
24753
34852
44852
54951
64951
74951
84951
94951
104951
114951
125050
135050
145050
155050
165050
175149
185149
195149
205149
215149
225149
235149
245149
255149
265149
275149
285149
295149
305149
315050

Chance of precipitation in August

Any precipitation

Portsmouth gets around 4.7 in of rain over 12.9 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 43% and peaks near 45% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
145
245
344
443
543
643
743
843
943
1043
1144
1244
1344
1444
1544
1644
1744
1844
1943
2043
2143
2242
2342
2441
2541
2641
2740
2840
2940
3040
3140

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the oppressive band about 48% of days. Sticky, muggy-or-worse air turns up on roughly 82% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
102921608
2021021607
3021021607
4021122596
5031123576
6031123576
7031124566
8031225546
9031226527
10031227517
11031227517
12031228507
13031229497
14031229487
15041230477
16041231467
17041331457
18041332456
19041333446
20041333445
21041433445
22041434435
23041533434
24041533434
25041633434
26041732433
27041832423
28151931423
29152030422
30152130422
31252129412

Wind in August

Winds average 6 mph in August, the calmest month.

Across August, 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 August

DaylightNight

Daylight runs from about 13 h 54 min 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 60 minutes over August. Sunrise moves from 5:14 AM to 5:39 AM, and sunset from 7:08 PM to 6:31 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.95:147:08
213.95:157:07
313.85:167:06
413.85:177:05
513.85:177:04
613.85:187:03
713.75:197:02
813.75:207:01
913.75:217:00
1013.65:226:59
1113.65:226:58
1213.65:236:57
1313.55:246:56
1413.55:256:54
1513.55:266:53
1613.45:276:52
1713.45:286:51
1813.35:286:49
1913.35:296:48
2013.35:306:47
2113.25:316:45
2213.25:326:44
2313.25:336:43
2413.15:336:41
2513.15:346:40
2613.15:356:38
2713.05:366:37
2813.05:376:36
2912.95:386:34
3012.95:386:33
3112.95:396:31

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.52 kWh/m².

For context, solar energy here swings from a low near 2.17 kWh/m² to a high of 6.42 kWh/m² in June across the year — August's 5.52 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.8Bright
25.8Bright
35.8Bright
45.7Bright
55.7Bright
65.7Bright
75.7Bright
85.7Bright
95.6Bright
105.6Bright
115.6Bright
125.6Bright
135.6Bright
145.5Bright
155.5Bright
165.5Bright
175.5Bright
185.5Bright
195.5Bright
205.4Bright
215.4Bright
225.4Bright
235.4Bright
245.3Bright
255.3Bright
265.3Bright
275.2Bright
285.2Bright
295.2Bright
305.1Bright
315.1Bright
Planning a trip in August

Hazard calendar for Portsmouth

In seasonPeak

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

Portsmouth 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 Portsmouth?

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

5.0
Sightseeing
7th-best month of the year
6.4
Beach & pool
2nd-best month of the year

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

What to pack for Portsmouth in August

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

In August, Portsmouth sees daytime highs around 85°F and nights near 71°F. Pack light clothes. Worth having: rain gear and sun protection. About 13 days see rain.

light clothesrain gearsun protection

Sea temperature near Portsmouth in August

The nearest coast averages about 79°F in August — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 22 mi away) is warmest in August at about 79°F and coldest in February near 41°F.

It's comfortable for a long swim from Jun 3 to Oct 14 — about 4.4 months when the water holds above 68°F.

40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan44Bracing
Feb41Bracing
Mar45Bracing
Apr54Bracing
May63Cool
Jun72Refreshing
Jul78Warm
Aug79Warm
Sep76Warm
Oct68Cool
Nov57Bracing
Dec49Bracing

UV index in Portsmouth 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 Portsmouth peaks around July 12 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateJul 12UV 9Dec 19UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7High
May8Very high
Jun9Very high
Jul9Very high
Aug7Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Moderate

Air quality in Portsmouth 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 Portsmouth is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (November, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1216 µg/m³Nov 237 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb9Good
Mar11Good
Apr12Good
May13Moderate
Jun16Moderate
Jul16Moderate
Aug14Moderate
Sep11Good
Oct7Good
Nov7Good
Dec7Good
Location & terrain

Where is Portsmouth?

Portsmouth sits at 36.8°N, 76.3°W, 10 ft above sea level, in United States. The nearest listed city is Norfolk, 1.2 mi away.

Topography around Portsmouth

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

Within 2 miles, the terrain around Portsmouth has only modest variations in elevation — a maximum elevation change of 72 ft around an average of 10 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 194 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 230 ft.

The land around Portsmouth is covered by artificial surfaces (52%) within 2 miles, trees (44%), artificial surfaces (22%) and water (20%) within 10 miles, and trees (42%) and water (38%) within 50 miles.

2 miles
72 ft
10 miles
194 ft
50 miles
230 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
August weather nearby: Norfolk 1.2 mi · Chesapeake 1.9 mi · Portsmouth Heights 3.7 mi · Newport News 12 mi · Hampton 14 mi · East Hampton 14 mi · Suffolk 17 mi · Virginia Beach 18 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 Portsmouth (36.8354°, -76.2983°, elevation 10 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). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).