Miles City, Montana climate: Normal weather by month, frost dates and records
Miles City's normal year runs from 9°F January nights to 89°F July afternoons, with 12.9 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 7.8°C, January lows of −13°C, July highs of 32°C, 327 mm of precipitation a year.
- NOAA stationMiles City F Wiley Field
- Station IDUSW00024037
- Location46.43°N 105.88°W
- Elevation2,624 ft (800 m)
- Population8,407
On October 14, the normal high in Miles City is 60°F and the normal low 35°F, and the chance of measurable rain or snow is 24%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Miles City.
- Jan 30° 9°
- Feb 35° 13°
- Mar 47° 23°
- Apr 58° 33°
- May 68° 43°
- Jun 79° 53°
- Jul 89° 60°
- Aug 87° 58°
- Sep 76° 47°
- Oct 59° 34°
- Nov 44° 21°
- Dec 33° 12°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Miles City each month?
July is the warmest month, with normal highs of 89°F; January the coldest, with normal lows of 9°F. The most precipitation falls in May (2.73 in), the least in December (0.22 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 30°F | 9°F | 19.5°F | 0.28 | 5 | <1 | 30 | 9 h |
| February | 35°F | 13°F | 23.6°F | 0.26 | 5 | <1 | 27 | 10 h 20 min |
| March | 47°F | 23°F | 34.7°F | 0.55 | 6 | <1 | 25 | 11 h 50 min |
| April | 58°F | 33°F | 45.5°F | 1.54 | 9 | <1 | 13 | 13 h 30 min |
| May | 68°F | 43°F | 55.5°F | 2.73 | 12 | 1 | 3 | 15 h |
| June | 79°F | 53°F | 65.6°F | 2.51 | 11 | 4 | <1 | 15 h 50 min |
| July | 89°F | 60°F | 74.2°F | 1.51 | 8 | 16 | <1 | 15 h 30 min |
| August | 87°F | 58°F | 72.5°F | 0.91 | 7 | 15 | <1 | 14 h 10 min |
| September | 76°F | 47°F | 61.2°F | 1.07 | 7 | 4 | 1 | 12 h 40 min |
| October | 59°F | 34°F | 46.4°F | 0.97 | 8 | <1 | 11 | 11 h |
| November | 44°F | 21°F | 32.7°F | 0.33 | 5 | <1 | 26 | 9 h 30 min |
| December | 33°F | 12°F | 22.4°F | 0.22 | 4 | <1 | 30 | 8 h 40 min |
| Year (annual) | 59°F | 34°F | 46.1°F | 12.88 | 87 | 41 | 166 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −1°C | −13°C | −6.9°C | 7 mm |
| February | 2°C | −11°C | −4.7°C | 7 mm |
| March | 8°C | −5°C | 1.5°C | 14 mm |
| April | 15°C | 0°C | 7.5°C | 39 mm |
| May | 20°C | 6°C | 13.1°C | 69 mm |
| June | 26°C | 11°C | 18.7°C | 64 mm |
| July | 32°C | 15°C | 23.4°C | 38 mm |
| August | 31°C | 14°C | 22.5°C | 23 mm |
| September | 24°C | 8°C | 16.2°C | 27 mm |
| October | 15°C | 1°C | 8.0°C | 25 mm |
| November | 7°C | −6°C | 0.4°C | 8 mm |
| December | 1°C | −11°C | −5.3°C | 6 mm |
NOAA publishes no 1991-2020 snowfall normal for this station, and no record within 25 miles keeps one, so snow is left out here rather than estimated.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00024037; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Miles City?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (7).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00024037.
When is the last frost in Miles City?
In Miles City, the last spring frost (32°F) comes after May 8 in half of years and after May 21 in one year in ten; the first autumn frost comes before September 30 in half of years and before September 17 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 81 year in 10 after May 21; 9 in 10 after April 26
- First autumn frost, half of years before
- September 301 year in 10 before September 17; 9 in 10 before October 14
NOAA puts the median frost-free season at 144 days, and the season without a hard freeze (28°F) at 163 days.
A hard freeze (28°F) comes after April 29 in half of springs and before October 8 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Miles City in zone 4b in ZIP code 59301, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Miles City's NOAA station is in zone 4b: the coldest night of a typical year reaches −24°F (30 complete years).
Frost dates for every NOAA station in Montana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00024037; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Miles City?
In a normal year in Miles City, 41 days a year reach 90°F (6 of them 100°F or more), 166 nights fall to 32°F or colder and 87 days bring measurable precipitation.
- Days at 90°F or more
- 41a normal year
- Days at 100°F or more
- 6a normal year
- Nights at 32°F or colder
- 166a normal year
- Days that stay below freezing
- 51high of 32°F or less
- Days with 0.01 inch of precipitation
- 87a normal year
The highest temperature in this station's record (since 1937) is 115°F, on July 12, 2026; the lowest is −38°F, on December 24, 1983.
The wettest calendar year on that record is 1978, with 20.28 in; the snowiest season is 1995–96, with 64.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00024037; records: ACIS (NOAA Regional Climate Centers), station USW00024037. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Miles City, and how clear are its skies?
The summer (June-August) dew point averages 48°F. The muggiest month is June, with an average dew point of 51°F; the driest air comes in December (12°F). April is the windiest month (11.1 mph on average), and July has the most clear or nearly clear hours (80%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 15°F | 72% | 57% | 9.4 mph | 57% | 29% |
| February | 16°F | 69% | 52% | 9.6 mph | 57% | 30% |
| March | 26°F | 58% | 38% | 10.6 mph | 53% | 30% |
| April | 34°F | 55% | 36% | 11.1 mph | 55% | 26% |
| May | 46°F | 58% | 40% | 10.2 mph | 56% | 24% |
| June | 51°F | 51% | 31% | 9.5 mph | 71% | 11% |
| July | 50°F | 43% | 25% | 9.2 mph | 80% | 8% |
| August | 44°F | 43% | 24% | 9.1 mph | 76% | 10% |
| September | 37°F | 52% | 32% | 9.6 mph | 70% | 17% |
| October | 27°F | 62% | 41% | 10.0 mph | 60% | 26% |
| November | 18°F | 71% | 54% | 9.2 mph | 58% | 28% |
| December | 12°F | 72% | 61% | 9.0 mph | 58% | 30% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024037. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Miles City?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Miles City, 4.1 kWh per square metre a day. July is the sunniest month (88%) and December the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 1.7 |
| February | 78% | 2.8 |
| March | 74% | 3.9 |
| April | 72% | 5.0 |
| May | 73% | 5.9 |
| June | 80% | 6.8 |
| July | 88% | 7.2 |
| August | 86% | 6.0 |
| September | 80% | 4.4 |
| October | 74% | 2.9 |
| November | 74% | 1.9 |
| December | 70% | 1.3 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Miles City need?
A normal year in Miles City brings 7,566 heating degree days, 41% more than the median U.S. place (5,373), and 731 cooling degree days, 19% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,630 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,410 | 0 |
| February | 1,159 | 0 |
| March | 941 | 0 |
| April | 586 | 1 |
| May | 310 | 15 |
| June | 81 | 97 |
| July | 10 | 294 |
| August | 24 | 256 |
| September | 176 | 64 |
| October | 581 | 4 |
| November | 968 | 0 |
| December | 1,320 | 0 |
| Year (annual) | 7,566 | 731 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00024037. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Miles City been warmer than normal lately?
2025 averaged 47.3°F, 1.2°F above the 1991-2020 normal of 46.1°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 47.7°F | +1.6°F | 9.60 |
| 2022 | 45.3°F | −0.8°F | 9.75 |
| 2023 | 47.7°F | +1.6°F | 14.61 |
| 2024 | 48.1°F | +2.0°F | 11.11 |
| 2025 | 47.3°F | +1.2°F | 13.18 |
Over 130 complete years from 1878 to 2025, the station's annual mean temperature rose at a fitted 3.8°F per century (+0.21°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00024037; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Miles City's climate compare?
Miles City is warmer than 113 of the other 140 places with their own NOAA record in Montana, and wetter than 29. Across the 7,247 U.S. stations with normals, its annual mean of 46.1°F is warmer than 24%.
In the Köppen classification computed from these normals, Miles City is BSk: cold semi-arid steppe. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Questions about Miles City's climate
What is the coldest month in Miles City?
January, with a normal high of 30°F and a normal low of 9°F. The warmest is July (89°F by day, 60°F at night).
What is the rainiest month in Miles City?
May, with 2.73 in of precipitation in a normal year; the driest is December with 0.22 in.
What plant hardiness zone is Miles City in?
The USDA's 2023 map puts Miles City in zone 4b in ZIP code 59301, the nearest ZIP area. By the same method at Miles City's NOAA station, the coldest night of a typical year reaches −24°F (30 years, 1991-2020): zone 4b.
How late can frost come in Miles City?
In half of years the last 32°F night comes after May 8; in one year in ten it comes after May 21. Waiting until May 21 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Miles City in OctoberThis month day by day, its records and recent years
- Montana climateThe statewide normals and every place in the state
- Mizpah (4 mi NNW), MT30 miles from this station, 46.1°F a year
- Rock Springs, MT32 miles from this station, 44.3°F a year
- Terry, MT37 miles from this station, 45.3°F a year
- Forsyth, MT39 miles from this station, 46.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made