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).
| 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 |
| 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.
| 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.
| 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.