December weather forecastRio Vista, MD
December
Weather in December
December, the first month of the winter in Rio Vista, is still a chilly month, with an average temperature ranging between min 36.5°F (2.5°C) and max 46.2°F (7.9°C).Temperature
Start of December brings a slight shift in the average high-temperature, dipping a bit from November's fresh 54.5°F (12.5°C) to a frosty 46.2°F (7.9°C). Rio Vista experiences an average nighttime temperature of 36.5°F (2.5°C) in the month of December.Humidity
The average relative humidity in December is 76%.Rainfall
In Rio Vista, in December, during 11.1 rainfall days, 2.91" (74mm) of precipitation is typically accumulated. Throughout the year, there are 157 rainfall days, and 32.91" (836mm) of precipitation is accumulated.Snowfall
January through April, November and December are months with snowfall. In Rio Vista, during December, snow falls for 1.6 days and regularly aggregates up to 0.67" (17mm) of snow. In Rio Vista, during the entire year, snow falls for 9.8 days and aggregates up to 3.82" (97mm) 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 Rio Vista, Maryland, sunrise is at 7:04 am and sunset at 4:43 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 4:53 pm EST.
Sunshine
The average sunshine in December is 5.3h.UV index
January and December, with an average maximum UV index of 2, are months with the lowest UV index in Rio Vista. A UV Index estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV radiation for the ordinary person.Note: The maximum daily UV index of 2 in December converts into the following recommendations:
Sun exposure does not present considerable issues for many, yet infants, fair-skinned people, and children necessitate constant protection. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Stay sun-safe with clothing that is both closely woven and worn loosely. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Rio Vista, MD
- Average high temperature in December: 46.2°F
The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (40.5°F).
- Average low temperature in December: 36.5°F
The month with the highest average low temperature is July (71.8°F).
The coldest month (with the lowest average low temperature) is January (30°F).
Average pressure in December
Rio Vista, MD
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Rio Vista, MD
- Average wind speed in December: 9.2mph
The windiest months (with the highest average wind speed) are February and March (10.1mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in December
Rio Vista, MD
- Average humidity in December: 76%
The month with the highest relative humidity is May (79%).
The months with the lowest relative humidity are January and November (73%).
Average rainfall in December
Rio Vista, MD
- Average rainfall in December: 2.91"
The wettest month (with the highest rainfall) is August (4.17").
The driest month (with the least rainfall) is January (1.93").
Average rainfall days in December
Rio Vista, MD
- Average rainfall days in December: 11.1 days
The month with the highest number of rainy days is May (17.2 days).
The months with the least rainy days are January and November (8.8 days).
Average snowfall in December
Rio Vista, MD
- Average snowfall in December: 0.67"
The month with the highest snowfall is March (1.22").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Rio Vista, MD
- Average snowfall days in December: 1.6 days
The month with the highest number of snowfall days is January (3.2 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Rio Vista, MD
- 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: 5h and 18min
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 12min).
Average sunshine days in December
Rio Vista, MD
- Average sunshine days in December: 17.7 days
The month with the most sunshine days is November (19.7 days).
The months with the least sunshine days are May and August (11.8 days).
Average UV index in December
Rio Vista, MD
- 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 and December (UV index 2).
Average cloud cover in December
Rio Vista, MD
- Average cloud cover in December: 43
The month with the most cloud cover is March (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 27).
Average visibility in December
Rio Vista, MD
- Average visibility in December: 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).





