January 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 January

A fresh start to the year in Portsmouth, Virginia, features weather conditions emblematic of a coastal winter. January weather provides cool temperatures with the average high and low of the month standing at 45.9°F (7.7°C) and 34.7°F (1.5°C) respectively. Residents might notice occasional light snowfall and the dominance of overcast skies. Given the coastal location, prevalent cloud cover and winds reaching 10.1mph (16.3km/h) depict a typical January. This January setting allows for ample indoor activities, promoting a warm start to the calendar year.

Temperature

January, marked by an average high-temperature of 45.9°F (7.7°C) and a low-temperature of 34.7°F (1.5°C), is the coldest month in Portsmouth.

Humidity

In Portsmouth, the average relative humidity in January is 75%.

Rainfall

In Portsmouth, in January, it is raining for 8.4 days, with typically 1.3" (33mm) of accumulated precipitation. Throughout the year, there are 151.9 rainfall days, and 20.35" (517mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through March, November and December. The month with the most snowfall in Portsmouth is January, when snow falls for 2.2 days and typically aggregates up to 0.47" (12mm) of snow.

Ocean temperature

In Portsmouth, in January, the average water temperature is 45.5°F (7.5°C).
Note: It is life-risking to swim in 45.5°F (7.5°C). Briefly staying in 55.4°F (13°C) waters feels unsettling, and temperatures below 50°F (10°C) might result in cold shock and loss of breath control, hinging on personal endurance.

Daylight

In Portsmouth, Virginia, the average length of the day in January is 9h and 59min.
On the first day of the month, sunrise is at 7:17 am and sunset at 4:59 pm. On the last day of January, sunrise is at 7:08 am and sunset at 5:28 pm EST.

Sunshine

In Portsmouth, Virginia, the average sunshine in January is 5.5h.

UV index

January is the month with the lowest UV index, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV radiation for ordinary individuals.
Note: In January, an average UV index of 2 transforms into the following instructions:
Extended sunlight exposure does not pose significant problems for most people, except for children, infants, and people with fair skin who always need shielding. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Updated: Aug 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the coldest months?

With average temperatures fluctuating between a high of 45.9°F (7.7°C) and a low of 34.7°F (1.5°C), January stands out as the coldest month.

What is the average January temperature?

In Portsmouth, in January, the average high-temperature is 45.9°F (7.7°C), and the average low-temperature is 34.7°F (1.5°C).

What is the average humidity in January?

In January, the average relative humidity is 75%.

How many days does it rain in January?

In Portsmouth, in January, it is raining for 8.4 days, with typically 1.3" (33mm) of accumulated precipitation.

When does it snow the most?

January is the month with the most snowfall. Snow falls for 2.2 days and accumulates 0.47" (12mm) of snow.

How much does it snow in January?

In Portsmouth, in January, snow falls for 2.2 days, with typically accumulated 0.47" (12mm) of snow.

What is the ocean temperature in January?

In January, the average ocean temperature is 45.5°F (7.5°C). Swimming in 45.5°F (7.5°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.

What is the average length of the day in January in Portsmouth?

The average day length in January is 9h and 59min.

What time are sunrise and sunset in January?

In January, on the first day of the month, sunrise is at 7:17 am and sunset at 4:59 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 5:28 pm EST.

How many hours of sunshine does Portsmouth have in January?

In January, the average sunshine duration is 5.5h.

What is the month with the lowest UV index?

With an average maximum UV index of 2, January is the month with the lowest UV index.

What is the UV index intensity in January?

In January, the average daily maximum UV index is 2. A UV Index estimate of 2, and below, represents a minimal hazard to health from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
Portsmouth, VA

Average temperature in January - Portsmouth, VA
  • Average high temperature in January: 45.9°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 January: 34.7°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 January
Portsmouth, VA

Average pressure in January - Portsmouth, VA
  • Average pressure in January: 30.11"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 January
Portsmouth, VA

Average wind speed in January - Portsmouth, VA
  • Average wind speed in January: 10.1mph

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 January
Portsmouth, VA

Average humidity in January - Portsmouth, VA
  • Average humidity in January: 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 January
Portsmouth, VA

Average rainfall in January - Portsmouth, VA
  • Average rainfall in January: 1.3"

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 January
Portsmouth, VA

Average rainfall days in January - Portsmouth, VA
  • Average rainfall days in January: 8.4 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 January
Portsmouth, VA

Average snowfall in January - Portsmouth, VA
  • Average snowfall in January: 0.47"

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 January
Portsmouth, VA

Average snowfall days in January - Portsmouth, VA
  • Average snowfall days in January: 2.2 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 January
Portsmouth, VA

Average sea temperature in January - Portsmouth, VA
  • Average sea temperature in January: 45.5°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 January /
Average sunshine in January
Portsmouth, VA

Average daylight in January / Average sunshine in January - Portsmouth, VA
  • Average daylight in January: 10h and 0min

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 January: 5h and 3min

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 January
Portsmouth, VA

Average sunshine days in January - Portsmouth, VA
  • Average sunshine days in January: 19 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 January
Portsmouth, VA

Average UV index in January - Portsmouth, VA
  • Average UV index in January: 2

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 January
Portsmouth, VA

Average cloud cover in January - Portsmouth, VA
  • Average cloud cover in January: 39

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 January
Portsmouth, VA

Average visibility in January - Portsmouth, VA
  • Average visibility in January: 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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