Bitterroot Valley Weather 
The Bitterroot Valley is known as the “Banana Belt” of Montana as the weather is far less severe than in other parts of the state. Bitterroot Valley weather is known for ideal summer conditions with daytime high’s normally in the 80’s and cool, crisp evenings that dip into the 40’s and 50’s.
Spring and fall are also mild and tend to be drier and warmer than the rest of Montana, and are excellent times to visit the area.
Winter brings cold temperatures and snow in December, January and February, although not as severe as in most parts of the state. The valley floor generally receives less than a foot of measurable snow each year, but the Lost Trail Ski Area commonly receives in excess of 200″ of snow per year only an hour’s drive from Hamilton.
Microclimates can be found throughout the valley due to the variety of elevations and bodies of water. Although generally pleasant, Bitterroot Valley weather can change quickly and we always recommend taking along a jacket or coat whenever you are outdoors.
Nights are cool throughout the year, creating pleasant sleeping conditions. Temperatures can reach 100 in late July and early August, and sub-zero temperatures are possible from late November into April, so plan accordingly with lots of layers.
Bitterroot Valley Weather Statistics
Average Rainfall: 12-15 inches per year.
Average Annual Snowfall at Lost Trail Ski Area: 200+ inches
Average Annual Snowfall on Valley Floor: 6 inches
Average Annual Sunny Days: 270
Average Annual Growing Days: 130-150
Daylight Hours – June 21: 16.5
Altitude: 3,200 – 3,890 feet
Bitterroot Valley Average Monthly Temperatures (ºF)
Month | High | Low |
---|---|---|
January | 34 | 16 |
February | 41 | 21 |
March | 48 | 25 |
April | 57 | 31 |
May | 66 | 38 |
June | 74 | 45 |
July | 83 | 49 |
August | 81 | 47 |
September | 70 | 39 |
October | 59 | 31 |
November | 43 | 23 |
December | 34 | 17 |