Bonner-West Riverside, MT climate
Bonner-West Riverside has chilly, snowy winters and pleasant summers, with very little rain. A typical July afternoon reaches 82°, a January night drops to 18°, and about 50 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Bonner-West Riverside feels like
Winter
Spring
Summer
Fall
Bonner-West Riverside weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 33° | 18° | 2.2" | 12.5" | 14 | 22 | 15° – 32° |
| February | 37° | 19° | 1.8" | 7.9" | 11 | 16 | 16° – 34° |
| March | 46° | 25° | 1.6" | 7.4" | 13 | 6 | 28° – 41° |
| April | 54° | 30° | 2.0" | 1.4" | 12 | 0 | 38° – 49° |
| May | 64° | 37° | 2.4" | 0.3" | 12 | 0 | 46° – 56° |
| June | 71° | 44° | 2.7" | 0.2" | 13 | 0 | 54° – 67° |
| July | 82° | 49° | 1.0" | 0 | 7 | 0 | 56° – 73° |
| August | 81° | 47° | 1.0" | 0 | 7 | 0 | 59° – 68° |
| September | 71° | 40° | 1.3" | 0 | 8 | 0 | 52° – 60° |
| October | 55° | 31° | 1.9" | 0.7" | 10 | 0 | 36° – 50° |
| November | 39° | 24° | 2.2" | 6.9" | 12 | 6 | 25° – 38° |
| December | 31° | 17° | 2.2" | 12.9" | 14 | 19 | 18° – 29° |
| Year | 55° | 32° | 22.2" | 50.2" | 132 | 70 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Bonner-West Riverside
Bonner-West Riverside gets 22 inches of rain and melted snow a year. June is the wettest month and August the driest. Rain or snow falls on about 132 days a year. Snow covers the ground about 70 days of the year.
About 143 frost-free days a year
In half of years the last 32° night comes by May 10 and the first one by October 1. That leaves about 143 frost-free days for gardens, shorter than 87% of U.S. towns.
Heating and cooling a home in Bonner-West Riverside
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Bonner-West Riverside, 95% of that work is heating and 5% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
How Bonner-West Riverside compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Bonner-West Riverside averaged 1.2° warmer than the 1900s. The biggest change is in January (+3.7°). The shift is smaller than in 52% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Bonner-West Riverside’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 16° to 34°. August is the most reliable, staying within 8°.
Common questions about Bonner-West Riverside’s climate
What is the coldest month in Bonner-West Riverside?
December, with a typical high of 31° and a low of 17°.
What is the hottest month in Bonner-West Riverside?
July, with a typical high of 82° and a low of 49°. About 22 days a year reach 90°.
How much snow does Bonner-West Riverside get?
About 50 inches in a normal winter, most of it in December.
When is the first frost in Bonner-West Riverside?
In half of years the first 32° night comes by October 1, and the last spring frost by May 10.
What is the rainiest month in Bonner-West Riverside?
June, with 2.7 inches of rain and melted snow. The year totals 22 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Bonner-West Riverside itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Missoula 2 Ne, MT (4 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.