August weather forecast
Portsmouth, VA

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Gold and brown trees and modern developed buildings in Downtown Portsmouth, Virginia
Gold and brown trees and modern developed buildings in Downtown Portsmouth, Virginia

Weather in August

Portsmouth's coastal summer rolls into August with all its glory and warmth. Despite a slight drop in peak temperatures, August sustains July's dynamic summer weather pattern. The slight decrease in humidity, coupled with cooling sea breeze, subtly reveals the imminent approach of fall. Moreover, the sea temperature peaks, inviting individuals for delightful swims and water sports. August stands as a blend of summer and impending fall, giving the people of Portsmouth the best of both.

Temperature

Portsmouth's average high-temperature in August is a moderately hot 84.7°F (29.3°C), marking an insignificant difference from the 86.4°F (30.2°C) of July. An average low-temperature of 73°F (22.8°C) is noted during the nights in August.

Heat index

Throughout August, the heat index is calculated to be a hot 93.2°F (34°C). Exercise more precautions, heat cramps and heat exhaustion are potential risks. Continuous activity could precipitate heatstroke.
In terms of the heat index, values are set with light wind and shade conditions in mind. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', integrates the air's temperature and its humidity to showcase the felt temperature by people. Depending on the activity and the individual's heat perception, which may vary due to factors including wind, clothing, and metabolic variations, this effect remains subjective. Always consider that direct sunlight exposure might heighten the heat's effects, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Young individuals are typically more threatened than adults due to their reduced perspiration. Also, the larger skin surface proportionate to their small bodies and the increased heat from their activities magnify their risk.

Humidity

In August, the average relative humidity is 75%.

Rainfall

The month with the most rainfall is August, when the rain falls for 16.9 days and typically aggregates up to 2.52" (64mm) of precipitation.

Snowfall

In Portsmouth, snow does not fall in April through October.

Ocean temperature

With an average ocean temperature of 80.1°F (26.7°C), August is the month with the warmest seawater.
Note: Water temperatures from 77°F (25°C) to 84.2°F (29°C) make swimming, diving, and similar activities highly pleasurable and enjoyable for long periods without discomfort.

Daylight

The average length of the day in August is 13h and 32min.
On the first day of August, sunrise is at 6:11 am and sunset at 8:11 pm. On the last day of the month, sunrise is at 6:35 am and sunset at 7:34 pm EDT.

Sunshine

The average sunshine in August is 10.6h.

UV index

July and August, with an average maximum UV index of 7, are months with the highest UV index. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for ordinary individuals.
Note: The maximum daily UV index of 7 in August interprets into the following recommendations:
Elude overexposure. Fair-skinned people could get burnt in less than 20 minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Attention! The reflection of both water and sand can increase the intensity of UV rays.
Updated: Aug 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is it hot during August?

The high-temperature, in August, in Portsmouth, records 84.7°F (29.3°C), while the low-temperature is 73°F (22.8°C). In August, the average heat index (a.k.a. 'real feel', 'felt air temperature'), which combines relative humidity and air temperature, is calculated to be 93.2°F (34°C).

What is the average humidity in August?

The average relative humidity in August is 75%.

What is the wettest month?

August is the month with the most rainfall. Rain falls for 16.9 days and accumulates 2.52" (64mm) of precipitation.

How much does it rain in Portsmouth in August?

In August, the rain falls for 16.9 days. Throughout August, 2.52" (64mm) of precipitation is accumulated.

When it does not snow?

In Portsmouth, Virginia, snow does not fall in April through October.

When is the ocean warmest?

The month with the warmest seawater is August, with an average ocean temperature of 80.1°F (26.7°C).

What is the water temperature in August?

In Portsmouth, Virginia, the average seawater temperature in August is 80.1°F (26.7°C). Water temperature between 77°F (25°C) and 84.2°F (29°C) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

What is the average length of the day in August?

In Portsmouth, Virginia, the average day length in August is 13h and 32min.

When is the sunrise / sunset in August?

On the first day of August in Portsmouth, sunrise is at 6:11 am and sunset at 8:11 pm. On the last day of the month, sunrise is at 6:35 am and sunset at 7:34 pm EDT.

How many hours of sunshine does Portsmouth have in August?

The average sunshine duration in August is 10.6h.

What are the months with the highest UV index in Portsmouth?

The months with the highest UV index are July and August, with an average maximum UV index of 7.

What is the UV index reading in August?

The average daily maximum UV index in August is 7. A UV Index value of 6 to 7 symbolizes a high health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
Portsmouth, VA

Average temperature in August - Portsmouth, VA
  • Average high temperature in August: 84.7°F

The warmest month (with the highest average high temperature) is July (86.4°F).
The month with the lowest average high temperature is January (45.9°F).

  • Average low temperature in August: 73°F

The month with the highest average low temperature is July (73.6°F).
The coldest month (with the lowest average low temperature) is January (34.7°F).

Average pressure in August
Portsmouth, VA

Average pressure in August - Portsmouth, VA
  • Average pressure in August: 29.99"Hg

The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.96"Hg).

Average wind speed in August
Portsmouth, VA

Average wind speed in August - Portsmouth, VA
  • Average wind speed in August: 7.5mph

The windiest months (with the highest average wind speed) are March and April (10.5mph).
The calmest month (with the lowest average wind speed) is August (7.5mph).

Average humidity in August
Portsmouth, VA

Average humidity in August - Portsmouth, VA
  • Average humidity in August: 75%

The month with the highest relative humidity is May (78%).
The months with the lowest relative humidity are July and November (74%).

Average rainfall in August
Portsmouth, VA

Average rainfall in August - Portsmouth, VA
  • Average rainfall in August: 2.52"

The wettest month (with the highest rainfall) is August (2.52").
The driest month (with the least rainfall) is November (1.1").

Average rainfall days in August
Portsmouth, VA

Average rainfall days in August - Portsmouth, VA
  • Average rainfall days in August: 16.9 days

The month with the highest number of rainy days is July (17.4 days).
The month with the least rainy days is November (8.3 days).

Average snowfall in August
Portsmouth, VA

Average snowfall in August - Portsmouth, VA
  • Average snowfall in August: 0"

The month with the highest snowfall is January (0.47").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in August
Portsmouth, VA

Average snowfall days in August - Portsmouth, VA
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (2.2 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).

Average sea temperature in August
Portsmouth, VA

Average sea temperature in August - Portsmouth, VA
  • Average sea temperature in August: 80°F

The best month for swimming (with the highest average sea temperature) is August (80°F).
The coldest month (with the lowest average sea temperature) is February (44.5°F).

Average daylight in August /
Average sunshine in August
Portsmouth, VA

Average daylight in August / Average sunshine in August - Portsmouth, VA
  • Average daylight in August: 13h and 3min

The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).

  • Average sunshine in August: 10h and 4min

The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 24min).

Average sunshine days in August
Portsmouth, VA

Average sunshine days in August - Portsmouth, VA
  • Average sunshine days in August: 10.8 days

The month with the most sunshine days is October (19.5 days).
The month with the least sunshine days is August (10.8 days).

Average UV index in August
Portsmouth, VA

Average UV index in August - Portsmouth, VA
  • Average UV index in August: 7

The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is January (UV index 2).

Average cloud cover in August
Portsmouth, VA

Average cloud cover in August - Portsmouth, VA
  • Average cloud cover in August: 29

The month with the most cloud cover is March (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 26).

Average visibility in August
Portsmouth, VA

Average visibility in August - Portsmouth, VA
  • Average visibility in August: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Portsmouth, Virginia, USA

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