December weather forecast and climate
Boise, ID

The golden fall season in Boise, Idaho
The golden fall season in Boise, Idaho
December, the first month of the winter, in Boise, is still a cold month, with average temperature fluctuating between 23.2°F (-4.9°C) and 34.7°F (1.5°C).

Temperature

The coldest month is December, with an average high-temperature of 34.7°F (1.5°C) and an average low-temperature of 23.2°F (-4.9°C).

Humidity

In December, the average relative humidity in Boise is 78%.

Rainfall

In Boise, in December, it is raining for 10.4 days, with typically 2.09" (53mm) of accumulated precipitation. In Boise, Idaho, during the entire year, the rain falls for 116.8 days and collects up to 15.08" (383mm) of precipitation.

Snowfall

January through April, November and December are months with snowfall. The month with the most snowfall is December when snow falls for 9.2 days and typically aggregates up to 6.65" (169mm) of snow.

Daylight

December has the shortest days of the year, with an average of 9h of daylight.

Sunshine

The month with the least sunshine in Boise is December, with an average of 5.5h of sunshine.

UV index

Months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low health risk from the exposure to the Sun's UV radiation for ordinary individuals.
Note: The daily maximum UV index of 2 in December interpret into the following advice:
People with sensitive skin, children, and babies should always be protected from prolonged 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. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.

What is the coldest month in Boise?

The coldest month in Boise is December, with an average high-temperature of 34.7°F (1.5°C) and an average low-temperature of 23.2°F (-4.9°C).

What is the temperature in December in Boise?

In Boise, Idaho, in December, the average high-temperature is 34.7°F (1.5°C), and the average low-temperature is 23.2°F (-4.9°C).

What is the average humidity in December in Boise?

In Boise, the average relative humidity in December is 78%.

How many days does it rain in December in Boise?

In Boise, in December, it is raining for 10.4 days, with typically 2.09" (53mm) of accumulated precipitation.

How much does it snow in Boise in December?

In Boise, in December, during 9.2 snowfall days, 6.65" (169mm) of snow is typically accumulated.

When does it snow the most in Boise?

The month with the most snowfall in Boise, Idaho, is December when snow falls for 9.2 days and typically aggregates up to 6.65" (169mm) of snow.

What is the month with the shortest days in Boise?

The month with the shortest days in Boise is December, with an average of 9h of daylight.

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

The average length of the day in December in Boise is 9h.

What is the month with the least sunshine in Boise?

With an average of 5.5h of sunshine, December has the least sunshine of the year.

How long on average sun shines in December in Boise?

The average sunshine in December in Boise is 5.5h.

When is the lowest UV index in Boise?

Months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.

How high is the UV index in December in Boise?

The average daily maximum UV index in December in Boise is 2. A UV Index value of 2, and less, symbolizes a low health risk from unsafe exposure to the Sun's UV rays.
Average temperature in December - Boise, ID
  • Average high temperature in December: 34.7°F

The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is December (34.7°F).

  • Average low temperature in December: 23.2°F

The month with the highest average low temperature is August (61.3°F).
The coldest month (with the lowest average low temperature) is December (23.2°F).

Average pressure in December - Boise, ID
  • Average pressure in December: 30.22"

The month with the highest atmospheric pressure is January (30.25").
The month with the lowest atmospheric pressure is June (29.9").

Average wind speed in December - Boise, ID
  • Average wind speed in December: 5.8mph

The windiest month (with the highest average wind speed) is April (7.1mph).
The calmest month (with the lowest average wind speed) is January (5.2mph).

Average humidity in December - Boise, ID
  • Average humidity in December: 78%

The month with the highest relative humidity is January (80%).
The month with the lowest relative humidity is July (30%).

Average rainfall in December - Boise, ID
  • Average rainfall in December: 2.09"

The wettest month (with the highest rainfall) is March (2.2").
The driest month (with the least rainfall) is July (0.2").

Average rainfall days in December - Boise, ID
  • Average rainfall days in December: 10.4 days

The month with the highest number of rainy days is March (16.2 days).
The month with the least rainy days is July (4.5 days).

Average snowfall in December - Boise, ID
  • Average snowfall in December: 6.65"

The month with the highest snowfall is December (6.65").
Months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in December - Boise, ID
  • Average snowfall days in December: 9.2 days

The month with the highest number of snowfall days is December (9.2 days).
Months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December / Average sunshine in December - Boise, ID
  • Average daylight in December: 9h

The month with the longest days is June (Average daylight: 15.4h).
The month with the shortest days is December (Average daylight: 9h).

  • Average sunshine in December: 5.5h

The month with the most sunshine is July (Average sunshine: 12.1h).
The month with the least sunshine is December (Average sunshine: 5.5h).

Average sunshine days in December - Boise, ID
  • Average sunshine days in December: 15.2 days

The month with the most sunshine days is July (23.6 days).
The month with the least sunshine days is March (12.1 days).

Average UV index in December - Boise, ID
  • Average UV index in December: 2

The month with the highest UV index is July (UV index 7).
Months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in December - Boise, ID
  • Average cloud cover in December: 42

The month with the most cloud cover is December (Cloud cover 42).
The month with the least cloud cover is July (Cloud cover 8).

Average visibility in December - Boise, ID
  • Average visibility in December: 6mi

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).