Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
The shift from November to December sees a distinct decrease in the average high-temperature, dropping from a chilly 43.3°F (6.3°C) to a freezing cold 28.2°F (-2.1°C). During the month of December, the temperature generally drops to a low average of 16.2°F (-8.8°C).Humidity
In December, the average relative humidity in Opal is 80%.Rainfall
In Opal, in December, during 4 rainfall days, 0.83" (21mm) of precipitation is typically accumulated. In Opal, South Dakota, during the entire year, the rain falls for 99.7 days and collects up to 16.06" (408mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Opal, during December, snow falls for 10.4 days and regularly aggregates up to 3.31" (84mm) of snow. In Opal, during the entire year, snow falls for 58.3 days and aggregates up to 22.95" (583mm) of snow.Daylight
The month with the shortest days in Opal is December, with an average of 8h and 54min of daylight.On the first day of the month, sunrise is at 7:08 am and sunset at 4:10 pm. On the last day of December, in Opal, South Dakota, sunrise is at 7:27 am and sunset at 4:18 pm MST.
Sunshine
In December, the average sunshine is 5.1h.UV index
The months with the lowest UV index in Opal are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: During December, 2 as the daily maximum UV index converts into the following advice:
Though the majority can handle prolonged sun exposure, it is crucial to always shield babies, children, and those with fair skin. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December in Opal?
What is the average humidity in December in Opal?
How much does it rain in Opal in December?
How many days does it snow in December in Opal?
What is the month with the shortest days in Opal?
How many hours of daylight does Opal have in December?
When are sunrise and sunset in December in Opal?
How many hours of sunshine does Opal have in December?
What are the months with the lowest UV index in Opal?
What is the UV index reading in December in Opal?
Average temperature in December
Opal, SD
- Average high temperature in December: 28.2°F
The warmest month (with the highest average high temperature) is July (87.3°F).
The month with the lowest average high temperature is January (27°F).
- Average low temperature in December: 16.2°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (13.6°F).
Average pressure in December
Opal, SD
- Average pressure in December: 30.14"Hg
The months with the highest atmospheric pressure are January and February (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in December
Opal, SD
- Average wind speed in December: 10.9mph
The windiest month (with the highest average wind speed) is April (12.2mph).
The calmest months (with the lowest average wind speed) are February and August (10.4mph).
Average humidity in December
Opal, SD
- Average humidity in December: 80%
The month with the highest relative humidity is January (83%).
The months with the lowest relative humidity are August and September (49%).
Average rainfall in December
Opal, SD
- Average rainfall in December: 0.83"
The wettest month (with the highest rainfall) is May (2.83").
The driest month (with the least rainfall) is January (0.51").
Average rainfall days in December
Opal, SD
- Average rainfall days in December: 4 days
The month with the highest number of rainy days is May (14.7 days).
The months with the least rainy days are January and February (3.3 days).
Average snowfall in December
Opal, SD
- Average snowfall in December: 3.31"
The month with the highest snowfall is February (5.12").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Opal, SD
- Average snowfall days in December: 10.4 days
The month with the highest number of snowfall days is January (12.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Opal, SD
- Average daylight in December: 8h and 5min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in December: 5h and 1min
The month with the most sunshine is July (Average sunshine: 11h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 48min).
Average sunshine days in December
Opal, SD
- Average sunshine days in December: 17.3 days
The month with the most sunshine days is September (20.4 days).
The month with the least sunshine days is April (12.4 days).
Average UV index in December
Opal, SD
- Average UV index in December: 2
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Opal, SD
- Average cloud cover in December: 47
The month with the most cloud cover is January (Cloud cover 50).
The months with the least cloud cover are July and August (Cloud cover 19).
Average visibility in December
Opal, SD
- 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).
Opal, South Dakota, USA
Weather forecast for your location
2. Allow the app to use your location