December weather forecast
Seneca, SD

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Weather in December

The first month of the winter, December, is also a subzero cold month in Seneca, South Dakota, with temperature in the range of an average high of 25.5°F (-3.6°C) and an average low of 14.2°F (-9.9°C).

Temperature

As Seneca welcomes December, the average high-temperature witnesses a distinct drop, moving from an icy 41.9°F (5.5°C) in November to a subzero cold 25.5°F (-3.6°C). In December, in Seneca, South Dakota, the average low-temperature is a still freezing cold 14.2°F (-9.9°C).

Humidity

The average relative humidity in December is 84%.

Rainfall

In Seneca, in December, during 3.3 rainfall days, 0.75" (19mm) of precipitation is typically accumulated. Throughout the year, there are 97.8 rainfall days, and 16.65" (423mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through May, October through December. In Seneca, in December, snow falls for 11.2 days, with typically accumulated 2.91" (74mm) of snow. In Seneca, during the entire year, snow falls for 59.7 days and aggregates up to 19.96" (507mm) of snow.

Daylight

The month with the shortest days is December, with an average of 8h and 48min of daylight.
On the first day of the month, sunrise is at 7:57 am and sunset at 4:57 pm. On the last day of December, sunrise is at 8:16 am and sunset at 5:06 pm CST.

Sunshine

In Seneca, the average sunshine in December is 4.4h.

UV index

January, February, November and December, with an average maximum UV index of 1, 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 average person.
Note: The maximum UV index of 1 during December leads to these instructions:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.

Frequently asked questions

How cold is December?

Seneca in December has an average high-temperature of 25.5°F (-3.6°C) and an average low-temperature of 14.2°F (-9.9°C). In August, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, is calculated to be 86°F (30°C).

What is the average humidity in December?

In Seneca, the average relative humidity in December is 84%.

How much does it rain in December?

In Seneca, during December, the rain falls for 3.3 days and regularly aggregates up to 0.75" (19mm) of precipitation.

How many days does it snow in December?

In Seneca, in December, snow falls for 11.2 days, with typically accumulated 2.91" (74mm) of snow.

What is the month with the shortest days in Seneca?

December has the shortest days of the year, with an average of 8h and 48min of daylight.

What is the average length of the day in December?

The average day length in December is 8h and 50min.

When are sunrise and sunset in December?

On the first day of December, sunrise is at 7:57 am and sunset at 4:57 pm. On the last day of the month, sunrise is at 8:16 am and sunset at 5:06 pm CST.

How long on average sun shines in December?

In December, the average sunshine duration in Seneca is 4.4h.

When is the lowest UV index?

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 1.

How high is the UV index in December?

In Seneca, the average daily maximum UV index in December is 1. A UV Index of 2, and less, symbolizes a minimal hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Seneca, SD

Average temperature in December - Seneca, SD
  • Average high temperature in December: 25.5°F

The warmest month (with the highest average high temperature) is July (85.8°F).
The month with the lowest average high temperature is January (22.6°F).

  • Average low temperature in December: 14.2°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 (9.1°F).

Average pressure in December
Seneca, SD

Average pressure in December - Seneca, SD
  • Average pressure in December: 30.14"Hg

The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).

Average wind speed in December
Seneca, SD

Average wind speed in December - Seneca, SD
  • Average wind speed in December: 10.4mph

The windiest month (with the highest average wind speed) is April (11.8mph).
The calmest month (with the lowest average wind speed) is August (9.7mph).

Average humidity in December
Seneca, SD

Average humidity in December - Seneca, SD
  • Average humidity in December: 84%

The month with the highest relative humidity is January (88%).
The months with the lowest relative humidity are August and September (56%).

Average rainfall in December
Seneca, SD

Average rainfall in December - Seneca, SD
  • Average rainfall in December: 0.75"

The wettest month (with the highest rainfall) is June (2.8").
The driest month (with the least rainfall) is January (0.55").

Average rainfall days in December
Seneca, SD

Average rainfall days in December - Seneca, SD
  • Average rainfall days in December: 3.3 days

The month with the highest number of rainy days is June (14.4 days).
The month with the least rainy days is February (1.9 days).

Average snowfall in December
Seneca, SD

Average snowfall in December - Seneca, SD
  • Average snowfall in December: 2.91"

The month with the highest snowfall is February (5.04").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Seneca, SD

Average snowfall days in December - Seneca, SD
  • Average snowfall days in December: 11.2 days

The month with the highest number of snowfall days is January (12.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Seneca, SD

Average daylight in December / Average sunshine in December - Seneca, SD
  • Average daylight in December: 8h and 5min

The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).

  • Average sunshine in December: 4h and 2min

The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).

Average sunshine days in December
Seneca, SD

Average sunshine days in December - Seneca, SD
  • Average sunshine days in December: 17.8 days

The month with the most sunshine days is November (21.1 days).
The month with the least sunshine days is June (13.1 days).

Average UV index in December
Seneca, SD

Average UV index in December - Seneca, SD
  • Average UV index in December: 1

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, November and December (UV index 1).

Average cloud cover in December
Seneca, SD

Average cloud cover in December - Seneca, SD
  • Average cloud cover in December: 53

The month with the most cloud cover is January (Cloud cover 58).
The months with the least cloud cover are July and August (Cloud cover 22).

Average visibility in December
Seneca, SD

Average visibility in December - Seneca, SD
  • Average visibility in December: 6mi

The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).

Seneca, South Dakota, USA

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