January weather forecast and climate
Boise, ID

The golden fall season in Boise, Idaho
The golden fall season in Boise, Idaho
January, the same as December, is a wintry winter month in Boise, Idaho, with average temperature varying between 23.4°F (-4.8°C) and 35.2°F (1.8°C).

Temperature

In Boise, the average high-temperature is essentially the same as in December - a still wintry 35.2°F (1.8°C). In January, the average low-temperature is 23.4°F (-4.8°C).

Humidity

The most humid month is January, with an average relative humidity of 80%.

Rainfall

In Boise, it is raining for 10.5 days, with typically 2.05" (52mm) 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 in Boise. In January, it is snowing for 8.2 days. Throughout January, 6.54" (166mm) of snow is accumulated. In Boise, during the entire year, snow falls for 31.4 days, and aggregates up to 21.3" (541mm) of snow.

Daylight

The average length of the day in January is 9.4h.

Sunshine

In Boise, the average sunshine is 5.7h.

UV index

Months with the lowest UV index in Boise are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health vulnerability from unprotected exposure to the Sun's UV rays for the average person.
Note: The average daily UV index of 2 in January transform into the following instructions:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. 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 35.2°F (1.8°C), and the average low-temperature is 23.4°F (-4.8°C).

What is the most humid month in Boise?

With an average relative humidity of 80%, January is the most humid month in Boise, Idaho.

What is the average humidity in January in Boise?

In January, the average relative humidity in Boise is 80%.

How many days does it rain in January in Boise?

In January, in Boise, Idaho, the rain falls for 10.5 days. Throughout January, 2.05" (52mm) of precipitation is accumulated.

How much does it snow in Boise in January?

In Boise, Idaho, during January, snow falls for 8.2 days and regularly aggregates up to 6.54" (166mm) of snow.

How many hours of daylight does Boise have in January?

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

How long on average sun shines in January in Boise?

In January, the average sunshine in Boise is 5.7h.

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 January in Boise?

In Boise, Idaho, the average daily maximum UV index in January is 2. A UV Index reading of 2, and below, represents a minimal health vulnerability from unsafe exposure to the Sun's UV rays.
Average temperature in January - Boise, ID
  • Average high temperature in January: 35.2°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 January: 23.4°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 January - Boise, ID
  • Average pressure in January: 30.25"

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 January - Boise, ID
  • Average wind speed in January: 5.2mph

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 January - Boise, ID
  • Average humidity in January: 80%

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

Average rainfall in January - Boise, ID
  • Average rainfall in January: 2.05"

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 January - Boise, ID
  • Average rainfall days in January: 10.5 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 January - Boise, ID
  • Average snowfall in January: 6.54"

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 January - Boise, ID
  • Average snowfall days in January: 8.2 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 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 the shortest days is December (Average daylight: 9h).

  • Average sunshine in January: 5.7h

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 January - Boise, ID
  • Average sunshine days in January: 15.8 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 January - Boise, ID
  • Average UV index in January: 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 January - Boise, ID
  • Average cloud cover in January: 40

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 January - Boise, ID
  • Average visibility in January: 5mi

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).