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
In December, the average high-temperature decreases considerably from a chilly 45.9°F (7.7°C) in November to a freezing cold 29.8°F (-1.2°C). Throughout December, an average low-temperature of 18°F (-7.8°C) is expected.Humidity
In Napa Junction, the average relative humidity in December is 82%.Rainfall
In Napa Junction, in December, during 3.7 rainfall days, 1.18" (30mm) of precipitation is typically accumulated. Throughout the year, there are 117.9 rainfall days, and 21.93" (557mm) of precipitation is accumulated.Snowfall
Months with snowfall in Napa Junction are January through May, October through December. December is the month with the most snowfall in Napa Junction. Snow falls for 8.1 days and accumulates 2.95" (75mm) of snow.Daylight
The month with the shortest days in Napa Junction is December, with an average of 9h and 6min of daylight.On the first day of the month, sunrise is at 7:41 am and sunset at 4:56 pm. On the last day of December, sunrise is at 8:00 am and sunset at 5:05 pm CST.
Sunshine
In December, the average sunshine is 4.7h.UV index
The average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for the average person.Note: The daily high UV index of 2 during December translates into the following recommendations:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.
Frequently asked questions
How cold is it in Napa Junction in December?
What is the average humidity in December in Napa Junction?
How many days does it rain in December in Napa Junction?
When does it snow the most in Napa Junction?
How many days does it snow in December in Napa Junction?
What is the month with the shortest days in Napa Junction?
How many hours of daylight does Napa Junction have in December?
What time are sunrise and sunset in December in Napa Junction?
How long on average sun shines in December in Napa Junction?
What is the UV index intensity in December in Napa Junction?
Average temperature in December
Napa Junction, SD
- Average high temperature in December: 29.8°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (26.8°F).
- Average low temperature in December: 18°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 (12.9°F).
Average pressure in December
Napa Junction, SD
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in December
Napa Junction, SD
- Average wind speed in December: 10.3mph
The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest month (with the lowest average wind speed) is July (7.9mph).
Average humidity in December
Napa Junction, SD
- Average humidity in December: 82%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is October (64%).
Average rainfall in December
Napa Junction, SD
- Average rainfall in December: 1.18"
The wettest month (with the highest rainfall) is May (3.78").
The driest month (with the least rainfall) is February (0.59").
Average rainfall days in December
Napa Junction, SD
- Average rainfall days in December: 3.7 days
The month with the highest number of rainy days is June (17.4 days).
The month with the least rainy days is February (2.3 days).
Average snowfall in December
Napa Junction, SD
- Average snowfall in December: 2.95"
The month with the highest snowfall is December (2.95").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Napa Junction, SD
- Average snowfall days in December: 8.1 days
The month with the highest number of snowfall days is January (9.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Napa Junction, SD
- Average daylight in December: 9h and 1min
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 December: 4h and 4min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in December
Napa Junction, SD
- Average sunshine days in December: 21.3 days
The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is June (9.3 days).
Average UV index in December
Napa Junction, SD
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Napa Junction, SD
- Average cloud cover in December: 48
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 25).
Average visibility in December
Napa Junction, 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).
Napa Junction, South Dakota, USA
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