December weather forecast
Darby, MT

Share

Weather in December

The first month of the winter, December, is still a freezing cold month in Darby, Montana, with temperature in the range of an average low of 14°F (-10°C) and an average high of 26.8°F (-2.9°C).

Temperature

Temperature readings reach their annual highs in December, averaging 26.8°F (-2.9°C) and a minimum average of 14°F (-10°C).

Humidity

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

Rainfall

In Darby, in December, during 12.9 rainfall days, 1.97" (50mm) of precipitation is typically accumulated. In Darby, during the entire year, the rain falls for 163.6 days and collects up to 20.83" (529mm) of precipitation.

Snowfall

January through May, September through December are months with snowfall. In Darby, in December, snow falls for 18.6 days, with typically accumulated 10.55" (268mm) of snow. In Darby, during the entire year, snow falls for 101.1 days and aggregates up to 59.17" (1503mm) of snow.

Daylight

The month with the shortest days is December, with an average of 8h and 42min of daylight.
On the first day of December, sunrise is at 7:59 am and sunset at 4:53 pm. On the last day of the month, sunrise is at 8:18 am and sunset at 5:01 pm MST.

Sunshine

January and December, with an average of 5.4h of sunshine, are months with the least sunshine.

UV index

The months with the lowest UV index are February and December, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for the ordinary person.
Note: In December, the maximum UV index of 1 suggests this advice:
Extended time in the sun generally does not harm most, but those with sensitive skin, infants, and children should always be protected. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

Frequently asked questions

What are the coldest months?

Temperature readings reach their annual highs in December, averaging 26.8°F (-2.9°C) and a minimum average of 14°F (-10°C).

How cold is it in December?

The high-temperature, in December, in Darby, is 26.8°F (-2.9°C), while the low-temperature averages to 14°F (-10°C).

What is the average humidity in December?

In December, the average relative humidity is 87%.

How many days does it rain in December?

In Darby, during December, the rain falls for 12.9 days and regularly aggregates up to 1.97" (50mm) of precipitation.

How much does it snow in December?

In December, it is snowing for 18.6 days. Throughout December, 10.55" (268mm) of snow is accumulated.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 8h and 42min of daylight.

What is the average length of the day in December?

In Darby, the average day length in December is 8h and 43min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:59 am and sunset at 4:53 pm. On the last day of the month, sunrise is at 8:18 am and sunset at 5:01 pm MST.

What is the month with the least sunshine?

The months with the least sunshine are January and December, with an average of 5.4h of sunshine.

How many hours of sunshine does Darby have in December?

In Darby, Montana, the average sunshine duration in December is 5.4h.

What is the month with the lowest UV index?

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

What is the UV index intensity in December?

The average daily maximum UV index in December is 1. A UV Index reading of 2, and below, represents 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
Darby, MT

Average temperature in December - Darby, MT
  • Average high temperature in December: 26.8°F

The warmest month (with the highest average high temperature) is July (77°F).
The month with the lowest average high temperature is December (26.8°F).

  • Average low temperature in December: 14°F

The month with the highest average low temperature is August (46.9°F).
The coldest month (with the lowest average low temperature) is December (14°F).

Average pressure in December
Darby, MT

Average pressure in December - Darby, MT
  • Average pressure in December: 30.19"Hg

The month with the highest atmospheric pressure is January (30.21"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Darby, MT

Average wind speed in December - Darby, MT
  • Average wind speed in December: 5.2mph

The windiest month (with the highest average wind speed) is January (5.3mph).
The calmest month (with the lowest average wind speed) is August (4.1mph).

Average humidity in December
Darby, MT

Average humidity in December - Darby, MT
  • Average humidity in December: 87%

The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (50%).

Average rainfall in December
Darby, MT

Average rainfall in December - Darby, MT
  • Average rainfall in December: 1.97"

The wettest months (with the highest rainfall) are February and April (2.36").
The driest month (with the least rainfall) is August (0.75").

Average rainfall days in December
Darby, MT

Average rainfall days in December - Darby, MT
  • Average rainfall days in December: 12.9 days

The month with the highest number of rainy days is May (19.5 days).
The month with the least rainy days is July (8 days).

Average snowfall in December
Darby, MT

Average snowfall in December - Darby, MT
  • Average snowfall in December: 10.55"

The month with the highest snowfall is February (13.03").
The months with the least snowfall are June, July and August (0").

Average snowfall days in December
Darby, MT

Average snowfall days in December - Darby, MT
  • Average snowfall days in December: 18.6 days

The month with the highest number of snowfall days is February (19.3 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in December /
Average sunshine in December
Darby, MT

Average daylight in December / Average sunshine in December - Darby, MT
  • Average daylight in December: 8h and 4min

The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).

  • Average sunshine in December: 5h and 2min

The months with the most sunshine are July and August (Average sunshine: 11h and 42min).
The months with the least sunshine are January and December (Average sunshine: 5h and 24min).

Average sunshine days in December
Darby, MT

Average sunshine days in December - Darby, MT
  • Average sunshine days in December: 10 days

The month with the most sunshine days is July (18.9 days).
The month with the least sunshine days is February (5.6 days).

Average UV index in December
Darby, MT

Average UV index in December - Darby, MT
  • Average UV index in December: 1

The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are February and December (UV index 1).

Average cloud cover in December
Darby, MT

Average cloud cover in December - Darby, MT
  • Average cloud cover in December: 48

The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 13).

Average visibility in December
Darby, MT

Average visibility in December - Darby, MT
  • Average visibility in December: 4mi

The months with the highest visibility are May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, March and December (4mi).

Darby, Montana, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location