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, like December, in Boise, Idaho, is a wintry winter month, with average temperature ranging between min 23.4°F (-4.8°C) and max 35.2°F (1.8°C).

Temperature

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

Humidity

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

Rainfall

In Boise, during January, the rain falls for 10.5 days and regularly aggregates up to 2.05" (52mm) of 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 Boise, during 8.2 snowfall days, 6.54" (166mm) of snow is typically accumulated. Throughout the year, there are 31.4 snowfall days, and 21.3" (541mm) of snow is accumulated.

Daylight

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

Sunshine

In January, the average sunshine is 5.7h.

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 of 2, and less, symbolizes a low health risk from unprotected exposure to the Sun's UV rays for the average person.
Note: In January, the average maximum UV index of 2 translate into the following recommendations:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from 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. 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. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the temperature in January in Boise?

The average high-temperature, in January, in Boise, Idaho, is 35.2°F (1.8°C), while the average low-temperature is 23.4°F (-4.8°C).

What is the most humid month in Boise?

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

What is the average humidity in January in Boise?

The average relative humidity in January 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 many days does it snow in January in Boise?

In Boise, 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?

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

How long on average sun shines in January in Boise?

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

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

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

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 of 2, and less, symbolizes a low health risk from unsafe exposure to the Sun's UV rays.
Average temperature in January - Boise, ID
  • Average high temperature in January: 1.8°C

The warmest month (with the highest average high temperature) is July (31°C).
The month with the lowest average high temperature is December (1.5°C).

  • Average low temperature in January: -4.8°C

The month with the highest average low temperature is August (16.3°C).
The coldest month (with the lowest average low temperature) is December (-4.9°C).

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: 52mm

The wettest month (with the highest rainfall) is March (56mm).
The driest month (with the lowest rainfall) is July (5mm).

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 lowest number of rainy days is July (4.5 days).

Average snowfall in January - Boise, ID
  • Average snowfall in January: 166mm

The month with the highest snowfall is December (169mm).
Months with the lowest snowfall are May, June, July, August, September and October (0mm).

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 lowest number of 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 shortest days is December (Average daylight: 9h).

  • Average sunshine in January: 5.7h

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

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).