December weather forecast
Erwin, SD

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Weather in December

December, the first month of the winter in Erwin, is still a freezing cold month, with an average temperature varying between 12.4°F (-10.9°C) and 23.7°F (-4.6°C).

Temperature

The arrival of December brings a significant change in Erwin's weather, with average high-temperatures dropping from November's icy 40.1°F (4.5°C) to a freezing cold 23.7°F (-4.6°C). In the month of December, the average temperature in Erwin, South Dakota, dips to an extreme cold 12.4°F (-10.9°C) during the night.

Humidity

The average relative humidity in December is 87%.

Rainfall

In December, the rain falls for 3.5 days. Throughout December, 0.75" (19mm) of precipitation is accumulated. In Erwin, South Dakota, during the entire year, the rain falls for 112.3 days and collects up to 18.78" (477mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall in Erwin. The months with the most snowfall in Erwin are January and December, with an average 3.74" (95mm) of accumulated snow.

Daylight

December has the shortest days of the year, with an average of 8h and 54min of daylight.
On the first day of the month, sunrise is at 7:46 am and sunset at 4:51 pm. On the last day of December, in Erwin, sunrise is at 8:06 am and sunset at 5:00 pm CST.

Sunshine

In December, the average sunshine is 4h.

UV index

January and December, with an average maximum UV index of 1, are months with the lowest UV index in Erwin. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for the average person.
Note: The maximum daily UV index of 1 in December converts into the following recommendations:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. When the Sun is at its strongest around midday, find shade and limit exposure. Boost your sun resistance with garments that are densely woven yet spacious. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.
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Frequently asked questions

How cold is it in Erwin in December?

In Erwin, in December, the average high-temperature is 23.7°F (-4.6°C), and the average low-temperature is 12.4°F (-10.9°C). In July, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which combines air temperature and relative humidity, is computed to be 84.2°F (29°C).

What is the average humidity in December in Erwin?

In December, the average relative humidity in Erwin is 87%.

How much does it rain in Erwin in December?

In Erwin, during December, the rain falls for 3.5 days and regularly aggregates up to 0.75" (19mm) of precipitation.

When does it snow the most in Erwin?

The months with the most snowfall in Erwin, South Dakota, are January and December, with an average 3.74" (95mm) of accumulated snow.

How much does it snow in Erwin in December?

In Erwin, South Dakota, in December, snow falls for 13 days, with typically accumulated 3.74" (95mm) of snow.

What is the month with the shortest days in Erwin?

December has the shortest days of the year in Erwin, with an average of 8h and 54min of daylight.

What is the average length of the day in December in Erwin?

In December, the average day length in Erwin, South Dakota, is 8h and 54min.

When is the sunrise / sunset in December in Erwin?

In December, on the first day of the month, sunrise is at 7:46 am and sunset at 4:51 pm. On the last day of the month, in Erwin, South Dakota, sunrise is at 8:06 am and sunset at 5:00 pm CST.

How long on average sun shines in December in Erwin?

In December, the average sunshine duration in Erwin, South Dakota, is 4h.

When is the lowest UV index in Erwin?

The months with the lowest UV index in Erwin, South Dakota, are January and December, with an average maximum UV index of 1.

What is the UV index reading in December in Erwin?

The average daily maximum UV index in December in Erwin is 1. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to 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
Erwin, SD

Average temperature in December - Erwin, SD
  • Average high temperature in December: 23.7°F

The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (19.4°F).

  • Average low temperature in December: 12.4°F

The month with the highest average low temperature is July (60.8°F).
The coldest month (with the lowest average low temperature) is January (5.5°F).

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Average pressure in December
Erwin, SD

Average pressure in December - Erwin, SD
  • Average pressure in December: 30.13"Hg

The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).

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Average wind speed in December
Erwin, SD

Average wind speed in December - Erwin, SD
  • Average wind speed in December: 11mph

The windiest month (with the highest average wind speed) is April (11.6mph).
The calmest month (with the lowest average wind speed) is July (8.5mph).

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Average humidity in December
Erwin, SD

Average humidity in December - Erwin, SD
  • Average humidity in December: 87%

The month with the highest relative humidity is January (90%).
The months with the lowest relative humidity are September and October (68%).

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Average rainfall in December
Erwin, SD

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

The wettest month (with the highest rainfall) is June (3.19").
The driest months (with the least rainfall) are January and February (0.59").

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Average rainfall days in December
Erwin, SD

Average rainfall days in December - Erwin, SD
  • Average rainfall days in December: 3.5 days

The month with the highest number of rainy days is June (17.2 days).
The month with the least rainy days is February (2.7 days).

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Average snowfall in December
Erwin, SD

Average snowfall in December - Erwin, SD
  • Average snowfall in December: 3.74"

The months with the highest snowfall are January and December (3.74").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in December
Erwin, SD

Average snowfall days in December - Erwin, SD
  • Average snowfall days in December: 13 days

The month with the highest number of snowfall days is January (14.4 days).
The months with the least snowfall days are June, July and August (0 days).

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

Average daylight in December / Average sunshine in December - Erwin, 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: 4h and 0min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).

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Average sunshine days in December
Erwin, SD

Average sunshine days in December - Erwin, SD
  • Average sunshine days in December: 16.3 days

The month with the most sunshine days is October (19.1 days).
The month with the least sunshine days is June (10.3 days).

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Average UV index in December
Erwin, SD

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

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).

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Average cloud cover in December
Erwin, SD

Average cloud cover in December - Erwin, SD
  • Average cloud cover in December: 59

The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 27).

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Average visibility in December
Erwin, SD

Average visibility in December - Erwin, 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).

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Erwin, South Dakota, USA

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