In Boise, summers are short, hot, dry and mostly clear, and winters are very cold, snowy and partly cloudy. Throughout the year,. Throughout the year, the temperature generally ranges from 24° F to 93° F and is rarely below 10° F or above 101° F. Boise, Idaho, receives 13 inches of rain, on average, per year.
The US average is 38 inches of rainfall per year. Boise has an average of 18 inches of snow per year. The average U.S. The US is 28 inches of snow per year.
Boise and the Treasure Valley have a high frequency of nighttime rainfall in the winter months, with 75 percent of the total between midnight and 8 a.m. local time. This nighttime precipitation occurs with astonishing regularity and often results in adverse travel conditions in the early morning hours with roads covered with ice, snow, rain or a combination of the three. Snowfall in Boise averages around 20 inches per year, but can range from a low of just a few inches to 30 to 40 inches.
With milder temperatures frequently in Treasure Valley during the winter, snowfalls are not as big as elsewhere in mid-latitudes. In contrast, the surrounding mountains receive abundant snowfall in a normal year due to higher elevation, cooler temperatures and the effects of the mountain's orographic wind flow that produce these increased amounts of snow. The greatest snows and winter weather events of greatest impact in the Treasure Valley occur when cold air is trapped on the surface, usually after a prolonged reversal event, then warmer humid air invades the shallow cold surface air producing snow. In this example, several inches of snow can fall and some of the biggest snowfalls in Boise have occurred this way.
In some cases, cold air from the valley is blown away by strong southeastern winds that tend to warm and dry the air, causing a change to rain or no precipitation. Even so, there are other times when there are rain shadow effects from the Owyhee Mountains to the southwest. In this case, the Valley endpoints in Ontario and Mountain Home receive measurable rainfall while Boise remains dry. Cold frontal passages in winter produce shorter snow showers, but can collect dust a couple of inches behind the cold front, but usually not in large quantities.
The city of Boise is located in Treasure Valley, which is part of the largest Snake River Valley in southern Idaho. The estimated value in Boise is calculated as the weighted average of the individual contributions of each station, with weights proportional to the inverse of the distance between Boise and a given station. The first few weeks of spring in Boise bring pretty much every type of weather Boise has to offer, from hail to warm sun, fast snow, wind and rain. You can search all the weather data about Boise you want and you still don't know what the weather is REALLY like in Boise.
BestPlaces's annual comfort index for Boise is 7.3 (10% 3Dbest), which means it's one of the nicest places in Idaho.