December weather forecastPortsmouth, OH
December
Weather in December
December, the first month of the winter in Portsmouth, is still a chilly month, with an average temperature varying between 43°F (6.1°C) and 31.1°F (-0.5°C).Temperature
With the beginning of December, the average high-temperature shows a decrease, transitioning from a fresh 52°F (11.1°C) in November to a chilly 43°F (6.1°C). In December, the recorded average low-temperature is a subzero cold 31.1°F (-0.5°C).Humidity
The months with the highest humidity are February and December, with an average relative humidity of 81%.Rainfall
In Portsmouth, in December, during 13.4 rainfall days, 2.95" (75mm) of precipitation is typically accumulated. Throughout the year, there are 170.4 rainfall days, and 31.02" (788mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, October through December. In Portsmouth, during December, snow falls for 8.4 days and regularly aggregates up to 2.13" (54mm) of snow. In Portsmouth, Ohio, during the entire year, snow falls for 36.7 days and aggregates up to 11.57" (294mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 30min of daylight.On the first day of December in Portsmouth, Ohio, sunrise is at 7:31 am and sunset at 5:10 pm. On the last day of the month, sunrise is at 7:49 am and sunset at 5:20 pm EST.
Sunshine
The average sunshine in December is 4.1h.UV index
January, February, November and 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 minimal health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: An average maximum UV index of 2 in December leads to these recommendations:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses. Remember this! The UV radiation of the Sun can be nearly doubled by the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Portsmouth, OH
- Average high temperature in December: 43°F
The warmest month (with the highest average high temperature) is July (86°F).
The month with the lowest average high temperature is January (37.8°F).
- Average low temperature in December: 31.1°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in December
Portsmouth, OH
- Average pressure in December: 30.14"Hg
The months with the highest atmospheric pressure are January and November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.96"Hg).
Average wind speed in December
Portsmouth, OH
- Average wind speed in December: 7mph
The windiest months (with the highest average wind speed) are January and February (7.5mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in December
Portsmouth, OH
- Average humidity in December: 81%
The months with the highest relative humidity are February and December (81%).
The month with the lowest relative humidity is August (75%).
Average rainfall in December
Portsmouth, OH
- Average rainfall in December: 2.95"
The wettest month (with the highest rainfall) is May (3.19").
The driest month (with the least rainfall) is September (1.85").
Average rainfall days in December
Portsmouth, OH
- Average rainfall days in December: 13.4 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is November (10.5 days).
Average snowfall in December
Portsmouth, OH
- Average snowfall in December: 2.13"
The month with the highest snowfall is January (3.19").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Portsmouth, OH
- Average snowfall days in December: 8.4 days
The month with the highest number of snowfall days is January (10.6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Portsmouth, OH
- Average daylight in December: 9h and 30min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 4h and 6min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in December
Portsmouth, OH
- Average sunshine days in December: 11.9 days
The month with the most sunshine days is November (17.3 days).
The month with the least sunshine days is February (10 days).
Average UV index in December
Portsmouth, OH
- Average UV index in December: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Portsmouth, OH
- Average cloud cover in December: 57
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in December
Portsmouth, OH
- Average visibility in December: 5mi
The months with the highest visibility are March, April, June, October and November (6mi).
The months with the lowest visibility are January, February, May, July, August, September and December (5mi).





