December weather forecast
Ortley, SD

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Weather in December

The first month of the winter, December, is also a subzero cold month in Ortley, South Dakota, with temperature in the range of an average low of 11.5°F (-11.4°C) and an average high of 23.2°F (-4.9°C).

Temperature

A decrease in the average high-temperature marks December, falling from November's wintry 38.8°F (3.8°C) to a subzero cold 23.2°F (-4.9°C). In December, the temperature drops to an average of 11.5°F (-11.4°C) at night.

Humidity

In December, the average relative humidity in Ortley, South Dakota, is 88%.

Rainfall

In Ortley, in December, it is raining for 4.1 days, with typically 0.98" (25mm) of accumulated precipitation. In Ortley, South Dakota, during the entire year, the rain falls for 112.9 days and collects up to 22.09" (561mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall. December is the month with the most snowfall in Ortley. Snow falls for 14.6 days and accumulates 4.53" (115mm) of snow.

Daylight

With an average of 8h and 48min of daylight, December has the shortest days of the year.
On the first day of December in Ortley, sunrise is at 7:48 am and sunset at 4:47 pm. On the last day of the month, sunrise is at 8:08 am and sunset at 4:56 pm CST.

Sunshine

In Ortley, the average sunshine in December is 3.6h.

UV index

January, November and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.
Note: A maximum high daily UV index of 1 during December translates into the following directions:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December in Ortley?

The high-temperature in Ortley during December is 23.2°F (-4.9°C) and the low-temperature is 11.5°F (-11.4°C). In July, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines relative humidity and air temperature, is computed to be 84.2°F (29°C).

What is the average humidity in December in Ortley?

In Ortley, South Dakota, the average relative humidity in December is 88%.

How much does it rain in Ortley in December?

In Ortley, during December, the rain falls for 4.1 days and regularly aggregates up to 0.98" (25mm) of precipitation.

What is the snowiest month in Ortley?

The month with the most snowfall in Ortley, South Dakota, is December, when snow falls for 14.6 days and typically aggregates up to 4.53" (115mm) of snow.

How many days does it snow in December in Ortley?

In Ortley, in December, snow falls for 14.6 days, with typically accumulated 4.53" (115mm) of snow.

What is the month with the shortest days in Ortley?

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

How many hours of daylight does Ortley have in December?

In Ortley, the average day length in December is 8h and 48min.

What time are sunrise and sunset in December in Ortley?

On the first day of December in Ortley, South Dakota, sunrise is at 7:48 am and sunset at 4:47 pm. On the last day of the month, sunrise is at 8:08 am and sunset at 4:56 pm CST.

How many hours of sunshine does Ortley have in December?

The average sunshine duration in December in Ortley, South Dakota, is 3.6h.

What are the months with the lowest UV index in Ortley?

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

How high is the UV index in December in Ortley?

The average daily maximum UV index in December in Ortley is 1. A UV Index reading of 2, and below, represents a minimal health vulnerability 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
Ortley, SD

Average temperature in December - Ortley, SD
  • Average high temperature in December: 23.2°F

The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (18.9°F).

  • Average low temperature in December: 11.5°F

The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (5°F).

Average pressure in December
Ortley, SD

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

The month with the highest atmospheric pressure is February (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).

Average wind speed in December
Ortley, SD

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

The windiest month (with the highest average wind speed) is April (11.7mph).
The calmest month (with the lowest average wind speed) is July (8.7mph).

Average humidity in December
Ortley, SD

Average humidity in December - Ortley, SD
  • Average humidity in December: 88%

The month with the highest relative humidity is January (91%).
The month with the lowest relative humidity is September (66%).

Average rainfall in December
Ortley, SD

Average rainfall in December - Ortley, SD
  • Average rainfall in December: 0.98"

The wettest month (with the highest rainfall) is July (3.58").
The driest month (with the least rainfall) is November (0.63").

Average rainfall days in December
Ortley, SD

Average rainfall days in December - Ortley, SD
  • Average rainfall days in December: 4.1 days

The month with the highest number of rainy days is June (17.9 days).
The month with the least rainy days is February (2.3 days).

Average snowfall in December
Ortley, SD

Average snowfall in December - Ortley, SD
  • Average snowfall in December: 4.53"

The month with the highest snowfall is December (4.53").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Ortley, SD

Average snowfall days in December - Ortley, SD
  • Average snowfall days in December: 14.6 days

The month with the highest number of snowfall days is January (15.1 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Ortley, 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: 3h and 4min

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 12min).

Average sunshine days in December
Ortley, SD

Average sunshine days in December - Ortley, SD
  • Average sunshine days in December: 15.2 days

The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is June (10.4 days).

Average UV index in December
Ortley, SD

Average UV index in December - Ortley, 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, November and December (UV index 1).

Average cloud cover in December
Ortley, SD

Average cloud cover in December - Ortley, SD
  • Average cloud cover in December: 62

The month with the most cloud cover is January (Cloud cover 66).
The months with the least cloud cover are July and August (Cloud cover 27).

Average visibility in December
Ortley, SD

Average visibility in December - Ortley, SD
  • Average visibility in December: 5mi

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

Ortley, South Dakota, USA

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