Few U.S. towns get less rain and snow than Garrison: 11 inches a year
The warmest part of a July day comes in at 83° on average. By January nights alone, it runs colder than 91% of U.S. towns. Decade by decade the climate has edged up, 1.4° above 1901–2000. From June to August, highs of 72–83° make it easy to spend the day outdoors.
A year in Garrison at a glance
Each month’s typical high and low, and what it brings.
What stands out about Garrison’s climate
Compared with towns across the U.S., with Garrison’s place in Montana beside it.
What a year in Garrison feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
A freeze is possible in every month
About 231 nights a year fall to 32° or below, and 24 to 0° or below. Frost and day counts come from NOAA’s station at Deer Lodge 3 W, MT, 10 miles from the town’s center, 380 ft higher.
The 2023 USDA map puts Garrison’s center in zone 4b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −23°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 31 inches of snow a winter
Snow, measured at Drummond Aviation, MT, falls mostly in December. Precipitation (rain plus melted snow) adds up to 11 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 103 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Garrison
99% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from September through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Deer Lodge 3 W, MT.
Living with Garrison’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 4b, and frost can come in any month. The longest frost-free stretch in half of years is about 65 days.
Months with highs of 62–84° and lows of 40° or more: June, July and August. 6.5 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Garrison from natural hazards, river flooding is the largest share (45%); heat waves, cold waves, winter storms and ice storms together are 14%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Garrison and similar climates
TownRatings has no climate map of the towns around Garrison yet.
Climates most like Garrison’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Garrison, MT | 12° | 83° | 11" | 31" |
| Taos, NM | 11° | 84° | 13" | 28" |
| Salida, CO | 10° | 85° | 8" | 37" |
| Cody, WY | 14° | 85° | 11" | 45" |
| Dickinson, ND | 5° | 83° | 16" | 35" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Garrison averaged 1.4° warmer than the 1900s. The biggest change is in January (+4.3°).
A bigger shift than in 54% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Garrison compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Garrison’s place among Montana’s.
Garrison weather by month
Highs, lows and precipitation from NOAA’s grid at Garrison’s center; snow, wet days and snow on the ground from Drummond Aviation, MT. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 33° | 12° | 0.4" | 5.3" | 10 | 17 | 13° – 30° |
| February | 36° | 13° | 0.5" | 4.8" | 8 | 12 | 10° – 34° |
| March | 46° | 21° | 0.6" | 4.7" | 8 | 5 | 23° – 39° |
| April | 55° | 27° | 0.9" | 1.7" | 10 | 0 | 36° – 47° |
| May | 64° | 35° | 1.6" | 0.9" | 10 | 0 | 44° – 55° |
| June | 72° | 41° | 2.0" | 0.7" | 11 | 0 | 53° – 63° |
| July | 83° | 46° | 1.1" | 0.0" | 7 | 0 | 55° – 70° |
| August | 82° | 43° | 1.0" | 0.2" | 7 | 0 | 58° – 67° |
| September | 72° | 36° | 0.9" | 0.1" | 6 | 0 | 50° – 59° |
| October | 56° | 27° | 0.7" | 0.7" | 8 | 0 | 34° – 47° |
| November | 41° | 18° | 0.5" | 5.0" | 9 | 7 | 21° – 37° |
| December | 32° | 11° | 0.5" | 6.4" | 10 | 16 | 13° – 27° |
| Year | 56° | 28° | 10.7" | 30.5" | 103 | 58 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 10° to 34°. September is the most reliable, staying within 9°.
Where Garrison’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Garrison’s center.
- Snow: Drummond Aviation, MT.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Deer Lodge 3 W, MT, 10 miles from the town’s center, 380 ft higher; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Garrison’s climate
What is the weather like in Garrison?
A typical July afternoon reaches 83°, a January night drops to 12°, and about 31 inches of snow falls in a normal winter. Colder January nights than 91% of U.S. towns; cooler July afternoons than 71% of U.S. towns.
How cold does it get in Garrison in winter?
December nights average 11°. About 231 nights a year reach 32° or below and 24 reach 0° or below. In the coldest December of the last 30 years the month averaged 13°.
How much snow does Garrison get?
About 31 inches in a normal winter at Drummond Aviation, MT, most of it in December, with snow on the ground about 58 days a year.
How hot does it get in Garrison?
July, with a typical high of 83° and a low of 46°. About 9 days a year reach 90° (Deer Lodge 3 W, MT).
When is the first and last frost in Garrison?
There is no reliable frost-free season: at Deer Lodge 3 W, MT, every month has nights at 32° or below, about 231 a year. In half of years the longest stretch without a freeze is about 65 days.
What growing zone is Garrison in?
Zone 4b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −23°.
What is the best time of year to visit Garrison?
By one simple rule (highs of 62–84° and lows of 40° or more), June, July and August. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Garrison getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 54% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Garrison.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.