Lewistown has cold, snowy winters and pleasant summers, with very little rain
A typical July afternoon reaches 82°, a January night drops to 12°, and about 112 inches of snow falls in a normal winter.
A year in Lewistown at a glance
Each month’s typical high and low, and what it brings.
What stands out about Lewistown’s climate
Read from where Lewistown sits among Montana’s towns. The page puts what stands out first.
112 inches of snow, 18 of rain and melt
June is the wettest month and February the driest. Rain or snow falls on about 98 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Warmer than it used to be
The last 30 years in Lewistown averaged 1.0° warmer than the 1900s. The biggest change is in January (+4.4°).
A smaller shift than in 69% of U.S. towns.
Change by month
What a year in Lewistown feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 119 frost-free days a year
In half of years the last 32° night comes by May 23 and the first by September 21.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
Living with Lewistown’s climate
What the numbers mean for a garden, a driveway, a furnace and a free afternoon.
119 frost-free days. The last frost comes by May 23 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Sep 21.
About 112" a winter over 37 days with an inch or more, most in March.
Months averaging under 55° run from October through May. Heating is 97% of the year’s heating-and-cooling load.
About 13 days a year reach 90°, and July afternoons average 82°.
The nicest months are June, July, August and September. 5.1 miles of trails are waiting.
Parks & trails →Normals are averages. Ice storms, nor’easters, floods and heat waves are on the natural hazards page.
Natural hazards →How Lewistown compares
Against every U.S. town on TownTapestry, each counted once, with its place in Montana.
Lewistown 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 | 35° | 12° | 0.6" | 17.5" | 7 | 13° – 35° |
| February | 37° | 13° | 0.5" | 16.4" | 7 | 4° – 36° |
| March | 46° | 21° | 0.9" | 19.5" | 8 | 19° – 42° |
| April | 54° | 28° | 1.8" | 17.2" | 9 | 35° – 46° |
| May | 64° | 37° | 3.1" | 3.1" | 11 | 46° – 55° |
| June | 72° | 45° | 3.4" | 0.2" | 13 | 54° – 64° |
| July | 82° | 50° | 1.8" | 0 | 10 | 57° – 73° |
| August | 82° | 49° | 1.6" | 0 | 8 | 59° – 71° |
| September | 71° | 40° | 1.5" | 2.1" | 7 | 51° – 62° |
| October | 57° | 30° | 1.4" | 8.8" | 7 | 35° – 49° |
| November | 45° | 20° | 0.7" | 11.2" | 6 | 23° – 42° |
| December | 36° | 13° | 0.5" | 16.1" | 6 | 13° – 32° |
| Year | 57° | 30° | 17.7" | 112.1" | 98 |
Heating and cooling a home in Lewistown
97% of the work is heating, so the furnace matters far more than the air conditioner.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. Source: NOAA station normals.
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 4° to 36°. May is the most reliable, staying within 9°.
Common questions about Lewistown’s climate
What is the coldest month in Lewistown?
January, with a typical high of 35° and a low of 12°.
What is the hottest month in Lewistown?
July, with a typical high of 82° and a low of 50°. About 13 days a year reach 90°.
How much snow does Lewistown get?
About 112 inches in a normal winter, most of it in March.
When is the first frost in Lewistown?
In half of years the first 32° night comes by September 21, and the last spring frost by May 23.
What is the rainiest month in Lewistown?
June, with 3.4 inches of rain and melted snow. The year totals 18 inches.
Neighbors talk weather
Gardens, snow, and the best days of the year in Lewistown.
Your answer becomes a post in Town Square.
Temperatures and rainfall come from NOAA’s gridded climate normals for Lewistown itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Lewistown 11 Sse, MT (10 mi, snow) and Lewistown Municipal Airport, 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. Today’s forecast: National Weather Service.