Graves Hotel · Photo: Mike Cline · Public domainPrecipitation in Harlowton trails that of 94% of U.S. towns: 13 inches a year
Midsummer highs settle at about 84°. The seasons are far apart: from a winter night to a summer afternoon the average spans 70°. Winter nights are cold: in January they are colder than in 87% of U.S. towns. The outdoor season, with highs of 73–83°, runs through June, August and September.
A year in Harlowton at a glance
Each month’s typical high and low, and what it brings.
What stands out about Harlowton’s climate
Compared with towns across the U.S., with Harlowton’s place in Montana beside it.
What a year in Harlowton feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 113 frost-free days a year
In half of years the last 32° night comes by May 23 and the first by September 16. Frost and day counts come from NOAA’s station at Harlowton, MT, 0.4 miles from the town’s center, at about the same height.
The 2023 USDA map puts Harlowton’s center in zone 4b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −24°. 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 20 inches of snow a winter
Snow, measured at Harlowton, MT, falls mostly in January, 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 71 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Harlowton
97% 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 Harlowton, MT.
Living with Harlowton’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
113 frost-free days in zone 4b. 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 16.
Months with highs of 62–84° and lows of 40° or more: June, August and September. 0.5 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Harlowton from natural hazards, river flooding is the largest share (59%); heat waves, cold waves, winter storms and ice storms together are 25%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Harlowton and similar climates
TownRatings has no climate map of the towns around Harlowton yet.
Climates most like Harlowton’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 |
|---|---|---|---|---|
| Harlowton, MT | 14° | 84° | 13" | 20" |
| Raton, NM | 15° | 85° | 16" | 25" |
| Shelley, ID | 14° | 87° | 11" | 15" |
| Show Low, AZ | 19° | 86° | 15" | 19" |
| Cimarron Hills, CO | 18° | 85° | 17" | 33" |
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 Harlowton averaged 1.1° warmer than the 1900s. The biggest change is in January (+4.2°).
A smaller shift than in 68% 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 Harlowton compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Harlowton’s place among Montana’s.
Harlowton weather by month
Highs, lows and precipitation from NOAA’s grid at Harlowton’s center; snow, wet days and snow on the ground from Harlowton, MT. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 37° | 14° | 0.3" | 3.7" | 4 | 16° – 33° |
| February | 39° | 14° | 0.4" | 1.9" | 3 | 7° – 37° |
| March | 48° | 22° | 0.6" | 2.6" | 5 | 23° – 42° |
| April | 55° | 28° | 1.6" | 3.1" | 8 | 36° – 46° |
| May | 65° | 37° | 2.4" | 0.3" | 9 | 47° – 55° |
| June | 74° | 44° | 2.6" | 0.0" | 11 | 55° – 64° |
| July | 84° | 50° | 1.5" | 0.0" | 8 | 58° – 74° |
| August | 83° | 48° | 1.2" | 0.0" | 6 | 60° – 71° |
| September | 73° | 40° | 1.0" | 0.1" | 5 | 53° – 62° |
| October | 58° | 30° | 0.8" | 0.6" | 5 | 36° – 50° |
| November | 46° | 21° | 0.5" | 3.6" | 4 | 25° – 41° |
| December | 37° | 14° | 0.4" | 3.7" | 3 | 16° – 33° |
| Year | 58° | 30° | 13.4" | 19.6" | 71 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 7° to 37°. May is the most reliable, staying within 9°.
Where Harlowton’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 Harlowton’s center.
- Snow: Harlowton, MT (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Harlowton, MT, 0.4 miles from the town’s center, at about the same height; 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 Harlowton’s climate
What is the weather like in Harlowton?
A typical July afternoon reaches 84°, a January night drops to 14°, and about 20 inches of snow falls in a normal winter. Colder January nights than 87% of U.S. towns; cooler July afternoons than 59% of U.S. towns.
How cold does it get in Harlowton in winter?
January nights average 14°. About 191 nights a year reach 32° or below and 19 reach 0° or below. In the coldest January of the last 30 years the month averaged 16°.
How much snow does Harlowton get?
About 20 inches in a normal winter at Harlowton, MT, most of it in January, November and December.
How hot does it get in Harlowton?
July, with a typical high of 84° and a low of 50°. About 21 days a year reach 90° (Harlowton, MT).
When is the first and last frost in Harlowton?
In half of years the last spring frost (32°) comes by May 23 and the first fall frost by September 16, about 113 frost-free days, at Harlowton, MT.
What growing zone is Harlowton in?
Zone 4b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −24°.
What is the best time of year to visit Harlowton?
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 Harlowton getting warmer?
Yes: 1991–2020 averaged 1.1° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 68% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Harlowton.
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.