Ennis, MT climate
Ennis has cold, snowy winters and warm summers, with very little rain. A typical July afternoon reaches 85°, a January night drops to 13°, and about 45 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Ennis feels like
Winter
Spring
Summer
Fall
Ennis 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 | 35° | 13° | 0.4" | 6.5" | 5 | 17 | 17° – 29° |
| February | 38° | 14° | 0.5" | 7.6" | 6 | 13 | 14° – 35° |
| March | 47° | 22° | 0.8" | 6.6" | 8 | 6 | 25° – 41° |
| April | 55° | 28° | 1.4" | 6.0" | 11 | 3 | 37° – 46° |
| May | 65° | 35° | 2.0" | 1.3" | 12 | 0 | 44° – 55° |
| June | 74° | 42° | 2.3" | 0.2" | 11 | 0 | 52° – 64° |
| July | 85° | 47° | 1.2" | 0 | 8 | 0 | 56° – 72° |
| August | 84° | 44° | 1.0" | 0 | 7 | 0 | 58° – 68° |
| September | 73° | 37° | 1.1" | 0.1" | 7 | 0 | 52° – 60° |
| October | 59° | 29° | 1.1" | 2.2" | 8 | 1 | 36° – 50° |
| November | 44° | 20° | 0.7" | 6.9" | 7 | 8 | 22° – 41° |
| December | 34° | 12° | 0.6" | 7.3" | 6 | 18 | 17° – 28° |
| Year | 58° | 29° | 13.1" | 44.7" | 94 | 65 |
“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 Ennis
Ennis gets 13 inches of rain and melted snow a year. June is the wettest month and January the driest. Rain or snow falls on about 94 days a year. Snow covers the ground about 65 days of the year.
About 78 frost-free days a year
In half of years the last 32° night comes by June 16 and the first one by September 4. That leaves about 78 frost-free days for gardens, shorter than 100% of U.S. towns.
Heating and cooling a home in Ennis
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Ennis, 99% of that work is heating and 1% 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 Ennis 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 Ennis averaged 1.2° warmer than the 1900s. The biggest change is in January (+3.8°). The shift is smaller than in 55% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Ennis’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 14° to 35°. September is the most reliable, staying within 8°.
Common questions about Ennis’s climate
What is the coldest month in Ennis?
December, with a typical high of 34° and a low of 12°.
What is the hottest month in Ennis?
July, with a typical high of 85° and a low of 47°. About 13 days a year reach 90°.
How much snow does Ennis get?
About 45 inches in a normal winter, most of it in February.
When is the first frost in Ennis?
In half of years the first 32° night comes by September 4, and the last spring frost by June 16.
What is the rainiest month in Ennis?
June, with 2.3 inches of rain and melted snow. The year totals 13 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Ennis itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Ennis, MT (1 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.