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 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
In Portsmouth, the lowest average temperatures are observed in January, with a high of 27.3°F (-2.6°C) and a low of 14.5°F (-9.7°C).Humidity
The most humid month is January, with an average relative humidity of 83%.Rainfall
January is the month with the least rainfall. Rain falls for 3.2 days and accumulates 0.43" (11mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Portsmouth, Iowa, in January, during 8.3 snowfall days, 1.57" (40mm) of snow is typically accumulated. In Portsmouth, during the entire year, snow falls for 31.5 days and aggregates up to 7.13" (181mm) of snow.Daylight
In January, the average length of the day is 9h and 34min.On the first day of January, sunrise is at 7:48 am and sunset at 5:02 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 5:35 pm CST.
Sunshine
With an average of 4.5h of sunshine, January has the least sunshine of the year in Portsmouth.UV index
January, February, October through December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for the average person.Note: In January, the maximum UV index of 2 transforms into these recommendations:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the coldest time of year?
How cold is it in January?
What is the most humid month?
What is the average humidity in January?
What is the driest month?
How much does it rain in January?
How much does it snow in January?
How many hours of daylight does Portsmouth have in January?
When is the sunrise / sunset in January in Portsmouth?
What is the month with the least sunshine?
How long on average sun shines in January?
What is the month with the lowest UV index?
What is the UV index reading in January?
Average temperature in January
Portsmouth, IA
- Average high temperature in January: 27.3°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (27.3°F).
- Average low temperature in January: 14.5°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (14.5°F).
Average pressure in January
Portsmouth, IA
- Average pressure in January: 30.16"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in January
Portsmouth, IA
- Average wind speed in January: 10.6mph
The windiest month (with the highest average wind speed) is April (10.9mph).
The calmest month (with the lowest average wind speed) is July (7.2mph).
Average humidity in January
Portsmouth, IA
- Average humidity in January: 83%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is October (68%).
Average rainfall in January
Portsmouth, IA
- Average rainfall in January: 0.43"
The wettest month (with the highest rainfall) is June (2.64").
The driest month (with the least rainfall) is January (0.43").
Average rainfall days in January
Portsmouth, IA
- Average rainfall days in January: 3.2 days
The month with the highest number of rainy days is June (16.1 days).
The month with the least rainy days is February (2.8 days).
Average snowfall in January
Portsmouth, IA
- Average snowfall in January: 1.57"
The month with the highest snowfall is February (2.09").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in January
Portsmouth, IA
- Average snowfall days in January: 8.3 days
The month with the highest number of snowfall days is January (8.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in January /
Average sunshine in January
Portsmouth, IA
- Average daylight in January: 9h and 4min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in January: 4h and 3min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in January
Portsmouth, IA
- Average sunshine days in January: 20.1 days
The month with the most sunshine days is December (21.6 days).
The month with the least sunshine days is June (11.4 days).
Average UV index in January
Portsmouth, IA
- Average UV index in January: 2
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in January
Portsmouth, IA
- Average cloud cover in January: 52
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 27).
Average visibility in January
Portsmouth, IA
- 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, Iowa, USA
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