Boise
Idaho, USA
Long-term weather forecast
Long-term weather forecast

January weather forecast and climate
Boise, ID

The golden fall season in Boise, Idaho, with the tall city buildings
The golden fall season in Boise, Idaho, with the tall city buildings
January, the same as December, is a wintry winter month in Boise, Idaho, with temperature in the range of an average low of 24.6°F (-4.1°C) and an average high of 37.8°F (3.2°C).

Temperature

In January, the average high-temperature is essentially the same as in December - a still cold 37.8°F (3.2°C). In Boise, Idaho, the average low-temperature is 24.6°F (-4.1°C).

Humidity

The most humid month is January, with an average relative humidity of 75%.

Rainfall

In January, the rain falls for 10.5 days. Throughout January, 1.2" (31.5mm) of precipitation is accumulated. Throughout the year, in Boise, there are 87.6 rainfall days, and 11.7" (297.9mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through April, October through December.

Daylight

In January, the average length of the day in Boise, Idaho, is 9.4h.

Sunshine

In January, the average sunshine is 3.5h.

UV index

Months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a low threat to health from unsafe exposure to the UV radiation for average individuals.
In January, the average maximum UV index of 1 translate into the following recommendations:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.

What is the temperature in January in Boise?

In Boise, Idaho, in January, the average high-temperature is 37.8°F (3.2°C), and the average low-temperature is 24.6°F (-4.1°C).

What is the most humid month in Boise?

January is the most humid month, with an average relative humidity of 75%.

What is the average humidity in January in Boise?

The average relative humidity in January in Boise, Idaho, is 75%.

How many days does it rain in January in Boise?

In Boise, Idaho, during January, the rain falls for 10.5 days and regularly aggregates up to 1.2" (31.5mm) of precipitation.

How much does it snow in Boise in January?

In January, it is snowing for 5.3 days. Throughout January, 5.1" (129.5mm) of snow is accumulated.

How many hours of daylight does Boise have in January?

In January, the average length of the day in Boise, Idaho, is 9.4h.

How many hours of sunshine does Boise have in January?

In Boise, Idaho, the average sunshine in January is 3.5h.

What is the month with the lowest UV index in Boise?

Months with the lowest UV index in Boise are January and December, with an average maximum UV index of 1.

How high is the UV index in January in Boise?

In Boise, the average daily maximum UV index in January is 1. A UV Index of 2, and less, symbolizes a low health risk from the exposure to the Sun's UV radiation.
Average temperature in January - Boise, ID
  • Average high temperature in January: 37.8°F

The warmest month (with the highest average high temperature) is July (91.2°F).
The month with the lowest average high temperature is December (37.5°F).

  • Average low temperature in January: 24.7°F

The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is December (24°F).

Average humidity in January - Boise, ID
  • Average humidity in January: 75%

The month with the highest relative humidity is January (75%).
The month with the lowest relative humidity is July (36.1%).

Average rainfall in January - Boise, ID
  • Average rainfall in January: 1.2"

The wettest month (with the highest rainfall) is December (1.6").
The driest month (with the lowest rainfall) is August (0.2").

Average rainfall days in January - Boise, ID
  • Average rainfall days in January: 10.5 days

The month with the highest number of rainy days is December (11.8 days).
The month with the lowest number of rainy days is August (2.4 days).

Average snowfall in January - Boise, ID
  • Average snowfall in January: 5.1"

The month with the highest snowfall is December (7").
Months with the lowest snowfall are May, June, July, August and September (0").

Average snowfall days in January - Boise, ID
  • Average snowfall days in January: 5.3 days

The month with the highest number of snowfall days is December (6 days).
Months with the lowest number of snowfall days are May, June, July, August and September (0 days).

Average daylight in January / Average sunshine in January - Boise, ID
  • Average daylight in January: 9.4h

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

  • Average sunshine in January: 3.5h

The month with most sunshine is July (Average sunshine: 12.9h).
The month with least sunshine is December (Average sunshine: 3.4h).

Average UV index in January - Boise, ID
  • Average UV index in January: 1

Months with the highest UV index are June and July (UV index 9).
Months with the lowest UV index are January and December (UV index 1).