Westby, MT climate
Westby has cold, snowy winters and pleasant summers, with very little rain. A typical July afternoon reaches 81°, a January night drops to 0°, and about 37 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Westby feels like
Winter
Spring
Summer
Fall
Westby 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 | 30-yr range |
|---|---|---|---|---|---|---|
| January | 20° | 0° | 0.5" | 6.6" | 2 | -3° – 26° |
| February | 24° | 4° | 0.3" | 5.7" | 2 | -7° – 28° |
| March | 37° | 16° | 0.6" | 7.0" | 3 | 12° – 38° |
| April | 54° | 28° | 1.0" | 3.4" | 3 | 30° – 48° |
| May | 66° | 39° | 2.1" | 0.9" | 6 | 48° – 59° |
| June | 74° | 50° | 3.3" | 0 | 10 | 58° – 68° |
| July | 81° | 54° | 2.3" | 0 | 7 | 61° – 74° |
| August | 81° | 52° | 1.5" | 0 | 5 | 61° – 72° |
| September | 71° | 42° | 1.2" | 0 | 3 | 51° – 63° |
| October | 54° | 29° | 0.9" | 2.2" | 3 | 33° – 47° |
| November | 36° | 16° | 0.5" | 4.3" | 2 | 13° – 38° |
| December | 24° | 5° | 0.5" | 6.4" | 3 | 2° – 25° |
| Year | 52° | 28° | 14.7" | 36.5" | 48 |
“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 Westby
Westby gets 15 inches of rain and melted snow a year. June is the wettest month and February the driest. Rain or snow falls on about 48 days a year.
About 125 frost-free days a year
In half of years the last 32° night comes by May 18 and the first one by September 21. That leaves about 125 frost-free days for gardens, shorter than 96% of U.S. towns.
Heating and cooling a home in Westby
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Westby, 97% of that work is heating and 3% 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.
Westby and its neighbors
Westby borders 1 town with climate data. January nights across them vary by 0.0°. Westby has both the coldest January nights (0°) and the hottest July afternoons (81°). Westby’s January low is 0° and its July high 81°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Westby 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 Westby averaged 1.6° warmer than the 1900s. The biggest change is in January (+4.8°). The shift is larger than in 78% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Westby’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 -7° to 28°. June is the most reliable, staying within 10°.
Common questions about Westby’s climate
What is the coldest month in Westby?
January, with a typical high of 20° and a low of 0°.
What is the hottest month in Westby?
July, with a typical high of 81° and a low of 54°. About 10 days a year reach 90°.
How much snow does Westby get?
About 37 inches in a normal winter, most of it in March.
When is the first frost in Westby?
In half of years the first 32° night comes by September 21, and the last spring frost by May 18.
What is the rainiest month in Westby?
June, with 3.3 inches of rain and melted snow. The year totals 15 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Westby itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Fortuna 1 W, ND (12 mi, snow) and Westby, MT (1 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.