Boise, Idaho, is located in the Treasure Valley, which gives it a high-desert climate. This geographic reality influences the city’s weather, resulting in patterns that differ from the mountainous regions of the state. This analysis provides data on the typical snowfall amounts and the practical realities of winter weather in the city proper.
Understanding Boise’s Average Snowfall
The official average annual snowfall for Boise is measured at the Boise Air Terminal (Gowen Field). Data from the 1991-2020 climate period show the city receives an average of 17.6 inches of snow each year. This figure is well below the national average for snowfall in the United States, which is approximately 28 inches annually. This relatively low total means Boise’s winters are generally milder compared to many other cities across the northern US.
This moderate annual total is characteristic of the high-desert climate, which features lower overall precipitation. Compared to other parts of Idaho, particularly the central and northern mountains, Boise receives noticeably less snow. The low average ensures that while the area experiences a distinct winter season, snow-related disruptions are often less severe.
Monthly Distribution of Snow Events
The majority of Boise’s annual snowfall occurs from late November through early March. Snow events are concentrated in the heart of winter, making December and January the snowiest months. On average, December receives the highest total, with about 5.6 inches of accumulation, followed closely by January, which averages 5.3 inches.
These two months account for over half of the city’s yearly total. November and February also contribute measurable amounts, averaging 2.0 and 3.3 inches, respectively. Snowfall tapers off in March, which sees an average of only 1.2 inches, and by April, accumulation is minimal, marking the end of the snow season.
How Long Snow Stays on the Ground
While the annual snowfall total is modest, a practical concern is how long the snow remains on the ground. Boise’s climate features relatively mild daytime high temperatures and abundant solar exposure, which causes snow to melt quickly after a storm. The city sees an inch or more of snow cover on the ground for only a small fraction of the winter season.
It is uncommon for a deep snowpack to develop in the valley floor, meaning snow retention is low. After a snowfall event, accumulation often melts within a few days once temperatures rise above freezing during the day. Consequently, the number of days with persistent snow cover is low.