Contents
- Weather in January
- Frequently asked questions
- Average temperature in January
- Average pressure in January
- Average wind speed in January
- Average humidity in January
- Average rainfall in January
- Average rainfall days in January
- Average snowfall in January
- Average snowfall days in January
- Average sea temperature in January
- Average daylight in January
- Average sunshine in January
- Average sunshine days in January
- Average UV index in January
- Average cloud cover in January
- Average visibility in January
Weather in January
Temperature
With average high and low temperatures of 31.8°F (-0.1°C) and 21.2°F (-6°C) respectively, January is Portsmouth's coldest month.Humidity
The average relative humidity in January is 79%.Rainfall
In Portsmouth, in January, it is raining for 7.5 days, with typically 2.05" (52mm) of accumulated precipitation. Throughout the year, there are 144.2 rainfall days, and 27.48" (698mm) of precipitation is accumulated.Snowfall
January through April, October through December are months with snowfall. January is the month with the most snowfall. Snow falls for 8.8 days and accumulates 4.02" (102mm) of snow.Ocean temperature
In Portsmouth, New Hampshire, the average seawater temperature in January is 41.5°F (5.3°C).Note: Navigating the 41.5°F (5.3°C) at 55.4°F (13°C) is no joy, and temperatures less than 50°F (10°C) can threaten breathing and cause a chilling shock, gauging personal stamina.
Daylight
In January, the average length of the day is 9h and 26min.On the first day of January, sunrise is at 7:14 am and sunset at 4:18 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 4:53 pm EST.
Sunshine
The average sunshine in January is 5.1h.UV index
The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a low health risk from exposure to the Sun's UV rays for average individuals.Note: During January, 2 as the daily maximum UV index converts into the following advice:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Stay alert! Snow's reflective properties can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What month is the coldest?
How cold is January?
What is the average humidity in January?
How much does it rain in January?
When does it snow the most?
How many days does it snow in January?
What is the ocean temperature in January?
What is the average length of the day in January?
What time are sunrise and sunset in January?
How many hours of sunshine does Portsmouth have in January?
What is the month with the lowest UV index?
How high is the UV index in January?
Average temperature in January
Portsmouth, NH
- Average high temperature in January: 31.8°F
The warmest month (with the highest average high temperature) is July (76.3°F).
The month with the lowest average high temperature is January (31.8°F).
- Average low temperature in January: 21.2°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (21.2°F).
Average pressure in January
Portsmouth, NH
- Average pressure in January: 29.99"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in January
Portsmouth, NH
- Average wind speed in January: 11.7mph
The windiest month (with the highest average wind speed) is January (11.7mph).
The calmest month (with the lowest average wind speed) is July (6.6mph).
Average humidity in January
Portsmouth, NH
- Average humidity in January: 79%
The month with the highest relative humidity is June (80%).
The months with the lowest relative humidity are April and November (75%).
Average rainfall in January
Portsmouth, NH
- Average rainfall in January: 2.05"
The wettest month (with the highest rainfall) is October (2.83").
The driest month (with the least rainfall) is September (1.54").
Average rainfall days in January
Portsmouth, NH
- Average rainfall days in January: 7.5 days
The month with the highest number of rainy days is June (15 days).
The month with the least rainy days is January (7.5 days).
Average snowfall in January
Portsmouth, NH
- Average snowfall in January: 4.02"
The month with the highest snowfall is January (4.02").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in January
Portsmouth, NH
- Average snowfall days in January: 8.8 days
The month with the highest number of snowfall days is January (8.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average sea temperature in January
Portsmouth, NH
- Average sea temperature in January: 41.5°F
The best month for swimming (with the highest average sea temperature) is August (65.6°F).
The coldest month (with the lowest average sea temperature) is March (38.5°F).
Average daylight in January /
Average sunshine in January
Portsmouth, NH
- Average daylight in January: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in January: 5h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).
Average sunshine days in January
Portsmouth, NH
- Average sunshine days in January: 15.9 days
The month with the most sunshine days is September (16.8 days).
The month with the least sunshine days is April (13.2 days).
Average UV index in January
Portsmouth, NH
- Average UV index in January: 2
The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in January
Portsmouth, NH
- Average cloud cover in January: 45
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in January
Portsmouth, NH
- 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, New Hampshire, USA
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