Dillon City Library · Photo: Robstutz · CC BY-SA 3.0Dillon’s winters are colder but less snowy than most of the U.S.
A typical July afternoon reaches 83°, a January night drops to 13°, and about 11 inches of snow falls in a normal winter.
A year in Dillon at a glance
Each month’s typical high and low, and what it brings.
What stands out about Dillon’s climate
Compared with towns across the U.S., with Dillon’s place in Montana beside it.
What a year in Dillon feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 98 frost-free days a year
In half of years the last 32° night comes by June 5 and the first by September 13. Frost and day counts come from NOAA’s station at Dillon U Of Montana Western, MT, 0.6 miles from the town’s center, at about the same height.
The 2023 USDA map puts Dillon’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −19°. 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 11 inches of snow a winter
Snow, measured at Dillon U Of Montana Western, MT, falls mostly in December. Precipitation (rain plus melted snow) adds up to 10 inches a year; June is the wettest month and January the driest. Rain or snow falls on about 78 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Dillon
99% 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 Dillon U Of Montana Western, MT.
Living with Dillon’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
98 frost-free days in zone 5a. The last frost comes by Jun 5 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 13.
Months with highs of 62–84° and lows of 40° or more: June, July and August. 0.7 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Dillon from natural hazards, earthquakes are the largest share (51%); heat waves, cold waves, winter storms and ice storms together are 22%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Dillon and similar climates
TownRatings has no climate map of the towns around Dillon yet.
Climates most like Dillon’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 |
|---|---|---|---|---|
| Dillon, MT | 13° | 83° | 10" | 11" |
| Powell, WY | 11° | 87° | 7" | 11" |
| Taos, NM | 11° | 84° | 13" | 28" |
| Show Low, AZ | 19° | 86° | 15" | 19" |
| Salida, CO | 10° | 85° | 8" | 37" |
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 Dillon averaged 1.7° warmer than the 1900s. The biggest change is in January (+3.9°).
A bigger shift than in 75% 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 Dillon compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Dillon’s place among Montana’s.
Dillon weather by month
Highs, lows and precipitation from NOAA’s grid at Dillon’s center; snow, wet days and snow on the ground from Dillon U Of Montana Western, MT. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 32° | 13° | 0.2" | 1.7" | 4 | 12° – 29° |
| February | 36° | 14° | 0.3" | 0.9" | 5 | 12° – 34° |
| March | 46° | 22° | 0.5" | 0.4" | 6 | 22° – 41° |
| April | 54° | 28° | 1.1" | 0.2" | 9 | 36° – 45° |
| May | 64° | 36° | 1.7" | 0.1" | 11 | 44° – 55° |
| June | 73° | 43° | 1.8" | 0.0" | 10 | 53° – 64° |
| July | 83° | 48° | 0.9" | 0.0" | 6 | 56° – 72° |
| August | 82° | 46° | 0.8" | 0.0" | 6 | 58° – 68° |
| September | 71° | 39° | 0.9" | 0.0" | 5 | 52° – 60° |
| October | 57° | 29° | 0.8" | 0.4" | 7 | 34° – 50° |
| November | 42° | 20° | 0.4" | 2.9" | 5 | 19° – 39° |
| December | 31° | 12° | 0.3" | 4.6" | 5 | 14° – 28° |
| Year | 56° | 29° | 9.6" | 11.2" | 78 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 12° to 34°. September is the most reliable, staying within 7°.
Where Dillon’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 Dillon’s center.
- Snow: Dillon U Of Montana Western, MT (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Dillon U Of Montana Western, MT, 0.6 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 Dillon’s climate
What is the weather like in Dillon?
A typical July afternoon reaches 83°, a January night drops to 13°, and about 11 inches of snow falls in a normal winter. Colder January nights than 90% of U.S. towns; cooler July afternoons than 69% of U.S. towns.
How cold does it get in Dillon in winter?
December nights average 12°. About 189 nights a year reach 32° or below and 14 reach 0° or below. In the coldest December of the last 30 years the month averaged 14°.
How much snow does Dillon get?
About 11 inches in a normal winter at Dillon U Of Montana Western, MT, most of it in December.
How hot does it get in Dillon?
July, with a typical high of 83° and a low of 48°. About 14 days a year reach 90° (Dillon U Of Montana Western, MT).
When is the first and last frost in Dillon?
In half of years the last spring frost (32°) comes by June 5 and the first fall frost by September 13, about 98 frost-free days, at Dillon U Of Montana Western, MT.
What growing zone is Dillon in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −19°.
What is the best time of year to visit Dillon?
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 Dillon getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 75% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Dillon.
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.