Photo: Chris06 · CC BY-SA 4.0Hardly any U.S. towns collect less precipitation than Ulm: 13 inches a year
January nights here settle around 14°. From frosty January to warm July, readings climb 70°. Winter nights are cold: in January they are colder than in 87% of U.S. towns. Plan time outside for June, August and September, when highs sit at 73–84°.
A year in Ulm at a glance
Each month’s typical high and low, and what it brings.
What stands out about Ulm’s climate
Compared with towns across the U.S., with Ulm’s place in Montana beside it.
What a year in Ulm feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 126 frost-free days a year
In half of years the last 32° night comes by May 19 and the first by September 24. Frost and day counts come from NOAA’s station at Great Falls International Airport, 8 miles from the town’s center, 310 ft higher.
The 2023 USDA map puts Ulm’s center in zone 4a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −25°. 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 66 inches of snow a winter
Snow, measured at Great Falls International Airport, falls mostly in January, February, March, April, November and December. Precipitation (rain plus melted snow) adds up to 13 inches a year; June is the wettest month and January 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
Heating and cooling a home in Ulm
96% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October 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 Great Falls International Airport.
Living with Ulm’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
126 frost-free days in zone 4a. The last frost comes by May 19 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 24.
Months with highs of 62–84° and lows of 40° or more: June, August and September. 3.5 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Ulm from natural hazards, river flooding is the largest share (45%); heat waves, cold waves, winter storms and ice storms together are 37%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Ulm and similar climates
TownRatings has no climate map of the towns around Ulm yet.
Climates most like Ulm’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 |
|---|---|---|---|---|
| Ulm, MT | 14° | 84° | 13" | 66" |
| Rexburg, ID | 12° | 84° | 13" | 70" |
| Cheyenne, WY | 16° | 85° | 15" | 65" |
| Durango, CO | 12° | 86° | 18" | 64" |
| Doney Park, AZ | 17° | 86° | 16" | 52" |
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 Ulm averaged 1.3° warmer than the 1900s. The biggest change is in January (+4.9°).
A smaller shift than in 58% 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 Ulm compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Ulm’s place among Montana’s.
Ulm weather by month
Highs, lows and precipitation from NOAA’s grid at Ulm’s center; snow, wet days and snow on the ground from Great Falls International Airport. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 36° | 14° | 0.4" | 9.2" | 7 | 14 | 13° – 37° |
| February | 38° | 15° | 0.4" | 10.1" | 8 | 11 | 0° – 39° |
| March | 47° | 22° | 0.5" | 10.1" | 8 | 8 | 18° – 44° |
| April | 56° | 30° | 1.5" | 9.4" | 10 | 3 | 38° – 48° |
| May | 66° | 39° | 2.2" | 1.9" | 11 | 1 | 48° – 57° |
| June | 74° | 46° | 2.6" | 0.3" | 12 | 0 | 57° – 66° |
| July | 84° | 52° | 1.1" | 0.0" | 7 | 0 | 58° – 76° |
| August | 84° | 50° | 1.1" | 0.3" | 7 | 0 | 60° – 71° |
| September | 73° | 42° | 1.2" | 0.8" | 7 | 0 | 52° – 63° |
| October | 58° | 32° | 0.9" | 5.2" | 7 | 3 | 36° – 52° |
| November | 44° | 23° | 0.5" | 9.2" | 7 | 8 | 21° – 44° |
| December | 36° | 16° | 0.4" | 9.6" | 7 | 11 | 14° – 36° |
| Year | 58° | 32° | 12.7" | 66.1" | 98 | 60 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 0° to 39°. June is the most reliable, staying within 9°.
Where Ulm’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 Ulm’s center.
- Snow: Great Falls International Airport.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Great Falls International Airport, 8 miles from the town’s center, 310 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 Ulm’s climate
What is the weather like in Ulm?
A typical July afternoon reaches 84°, a January night drops to 14°, and about 66 inches of snow falls in a normal winter. Colder January nights than 87% of U.S. towns; cooler July afternoons than 56% of U.S. towns.
How cold does it get in Ulm in winter?
January nights average 14°. About 168 nights a year reach 32° or below and 21 reach 0° or below. In the coldest January of the last 30 years the month averaged 13°.
How much snow does Ulm get?
About 66 inches in a normal winter at Great Falls International Airport, most of it in January, February, March, April, November and December, with snow on the ground about 60 days a year.
How hot does it get in Ulm?
July, with a typical high of 84° and a low of 52°. About 22 days a year reach 90° (Great Falls International Airport).
When is the first and last frost in Ulm?
In half of years the last spring frost (32°) comes by May 19 and the first fall frost by September 24, about 126 frost-free days, at Great Falls International Airport.
What growing zone is Ulm in?
Zone 4a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −25°.
What is the best time of year to visit Ulm?
By one simple rule (highs of 62–84° and lows of 40° or more), June, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Ulm getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 58% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Ulm.
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.