Boise Snowfall Totals & Accumulation Averages

This page pulls together information on when, how much and how often Boise, Idaho has snow.

There are data and descriptions here of how many days it snows and the total amount of snowfall that Boise usually gets. There are also monthly and yearly counts of the days that the city normally has heavy snowstorms and deep snow accumulated on the ground. Plus there's information on when Boise can expect the first and last snowfalls of the season.

The first set of monthly snow totals are averages for 2010 to 2019. All the other numbers are long-term historical averages based on weather data gathered from 1991 to 2020 at Boise's Gowen Field Air Terminal.

How Often it Snows in Boise

The next two tables list monthly and yearly totals for amount of snow and how many days it snows at least 0.1 inches (0.25 centimetres).

10-year snowfall averages at Boise, 2010 to 2019
Days   Inches Centi­metres
1.4 January 4.7 12.0
1.3 February 3.8 9.6
0.4 March 1.0 2.5
0.0 April 0.1 0.2
0.0 October 0.0 0.1
0.9 November 2.2 5.6
1.8 December 5.5 14.0
5.8 Year 17.4 44.1
30-year snowfall averages at Boise, 1991 to 2020
Days   Inches Centi­metres
5.2 January 5.3 13.5
3.3 February 3.3 8.4
1.6 March 1.2 3.0
0.3 April 0.1 0.3
0.1 October 0.1 0.3
2.2 November 2.0 5.1
5.5 December 5.6 14.2
18.2 Year 17.6 44.7

These averages don't show how much the snowfall in Boise varies from year to year.

In December, for instance, one in four years totals over 8.5 inches of snow. Another 25 percent of years receive less than 1.9 inches for the month.

Similarly in January, fresh snowfall in the heaviest years amounts to over 8.6 inches, while the lightest years get less than 1.5 inches.

New snow for February ranges from over 5.5 inches in heavy snowfall years to under 0.4 inches in light years.

When Boise Has Its First & Last Snowfalls

The first snowfall of winter for Boise usually arrives in November. Less commonly, snow doesn't arrive until December. Very rarely, October does get a light snow flurry.

The timing of the end of the snow season varies a lot from year to year in Boise. The last snowfall can happen in February, March or April.

Boise is normally free of snow every year from May to September.

How Many Snowstorms Boise Gets

Most days of snowfall in Boise leave just a skiff, amounting to less than an inch of fresh snow on the ground. For six days a year on average, the amount of new snow totals at least an inch.

Heavy snowstorms are uncommon for Boise. Snowstorms of over five inches a day normally don't occur most years. Major blizzards that dump ten inches or more in one day are not expected here.

Number of days per month and year on average in Boise with a total snowfall of at least 1, 3, 5 or 10 inches
1 inch
2.5 cm
3 inches
7.6 cm
  5 inches
12.7 cm
10 inches
25.4 cm
1.8 0.3 January 0.1 0.0
1.2 0.3 February 0.0 0.0
0.5 0.0 March 0.0 0.0
0.0 0.0 April 0.0 0.0
0.1 0.0 October 0.0 0.0
0.8 0.1 November 0.0 0.0
1.7 0.5 December 0.1 0.0
6.1 1.2 Year 0.2 0.0

How Much Snow Normally Accumulates in Boise

Boise has an inch or more of snow on the ground for just a small fraction of winter.

Typically on two to three days a year the snow covering Boise gets to five or more inches deep. In most years the snowpack never builds up to ten inches.

Average total days per month and year in Boise with snow depth of at least 1, 3, 5 or 10 inches on the ground
1 inch
2.5 cm
3 inches
7.6 cm
  5 inches
12.7 cm
10 inches
25.4 cm
6.4 3.0 January 1.5 0.2
2.6 0.9 February 0.1 0.0
0.5 0.0 March 0.0 0.0
1.8 0.3 November 0.2 0.0
5.9 2.0 December 1.0 0.0
17.2 6.2 Year 2.8 0.2
References

Jay Lawrimore, Ron Ray, Scott Applequist, Bryant Korzeniewski, Matthew Menne. 2016. Global Summary of the Month and Year, Version 1.0. NOAA National Centers for Environmental Information.

NOAA National Centers for Environmental Information (NCEI). Climate Normals.

Idaho Snowfall
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