Millegan (14 mi SE), Montana climate: Climate normals at a NOAA weather station
Millegan (14 mi SE)'s normal year runs from 11°F December nights to 80°F July afternoons, with 19.6 inches of precipitation and 149 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 4.9°C, December lows of −12°C, July highs of 27°C, 498 mm of precipitation a year.
- NOAA stationMillegan (14 mi SE)
- Station IDUSC00245712
- Location46.87°N 111.16°W
- Elevation4,970 ft (1,515 m)
On October 22, the normal high in Millegan (14 mi SE) is 51°F and the normal low 26°F, and the chance of measurable rain or snow is 23%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Millegan (14 mi SE).
- Jan 33° 11°
- Feb 35° 12°
- Mar 44° 20°
- Apr 52° 26°
- May 61° 34°
- Jun 70° 41°
- Jul 80° 46°
- Aug 80° 45°
- Sep 69° 37°
- Oct 54° 28°
- Nov 41° 19°
- Dec 32° 11°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Millegan (14 mi SE) each month?
July is the warmest month, with normal highs of 80°F; December the coldest, with normal lows of 11°F. The most precipitation falls in June (3.61 in), the least in December (0.82 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 33°F | 11°F | 22.3°F | 1.03 | 23.2 | 7 | <1 | 31 | 8 h 50 min |
| February | 35°F | 12°F | 23.4°F | 1.11 | 24.4 | 8 | <1 | 27 | 10 h 20 min |
| March | 44°F | 20°F | 31.9°F | 1.14 | 22.6 | 8 | <1 | 29 | 11 h 50 min |
| April | 52°F | 26°F | 39.0°F | 2.11 | 22.2 | 11 | <1 | 25 | 13 h 30 min |
| May | 61°F | 34°F | 47.6°F | 2.58 | 3.4 | 12 | <1 | 13 | 15 h |
| June | 70°F | 41°F | 55.5°F | 3.61 | 1.4 | 12 | <1 | 2 | 15 h 50 min |
| July | 80°F | 46°F | 63.3°F | 1.92 | 0.0 | 8 | 3 | <1 | 15 h 30 min |
| August | 80°F | 45°F | 62.2°F | 1.44 | 0.0 | 7 | 2 | 1 | 14 h 20 min |
| September | 69°F | 37°F | 53.3°F | 1.36 | 0.9 | 6 | 1 | 7 | 12 h 40 min |
| October | 54°F | 28°F | 41.3°F | 1.59 | 7.2 | 8 | <1 | 22 | 11 h |
| November | 41°F | 19°F | 29.8°F | 0.91 | 20.3 | 7 | <1 | 28 | 9 h 30 min |
| December | 32°F | 11°F | 21.7°F | 0.82 | 23.7 | 7 | <1 | 31 | 8 h 30 min |
| Year (annual) | 54°F | 28°F | 40.9°F | 19.62 | 149.3 | 101 | 6 | 215 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 1°C | −12°C | −5.4°C | 26 mm | 59 cm |
| February | 2°C | −11°C | −4.8°C | 28 mm | 62 cm |
| March | 7°C | −7°C | −0.1°C | 29 mm | 57 cm |
| April | 11°C | −3°C | 3.9°C | 54 mm | 56 cm |
| May | 16°C | 1°C | 8.7°C | 66 mm | 9 cm |
| June | 21°C | 5°C | 13.1°C | 92 mm | 4 cm |
| July | 27°C | 8°C | 17.4°C | 49 mm | 0 cm |
| August | 27°C | 7°C | 16.8°C | 37 mm | 0 cm |
| September | 21°C | 3°C | 11.8°C | 35 mm | 2 cm |
| October | 12°C | −2°C | 5.2°C | 40 mm | 18 cm |
| November | 5°C | −7°C | −1.2°C | 23 mm | 52 cm |
| December | 0°C | −12°C | −5.7°C | 21 mm | 60 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00245712; 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.
Which months are mildest at Millegan (14 mi SE)?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, September has the fewest days with rain (6).
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 USC00245712.
When is the last frost at Millegan (14 mi SE)?
In Millegan (14 mi SE), the last spring frost (32°F) comes after June 11 in half of years and after July 3 in one year in ten; the first autumn frost comes before September 6 in half of years and before August 20 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
- June 111 year in 10 after July 3; 9 in 10 after May 27
- First autumn frost, half of years before
- September 61 year in 10 before August 20; 9 in 10 before September 21
NOAA puts the median frost-free season at 86 days, and the season without a hard freeze (28°F) at 121 days.
A hard freeze (28°F) comes after May 20 in half of springs and before September 22 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Millegan (14 mi SE) in zone 4b in ZIP code 59645, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 4a: the coldest night of a typical year reaches −28°F (21 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Montana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00245712; 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 at Millegan (14 mi SE)?
In a normal year in Millegan (14 mi SE), 6 days a year reach 90°F, 215 nights fall to 32°F or colder and 101 days bring measurable precipitation.
- Days at 90°F or more
- 6a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 215a normal year
- Days that stay below freezing
- 46high of 32°F or less
- Days with 0.01 inch of precipitation
- 101a normal year
- Days with 1 inch of snow or more
- 43a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00245712.
How sunny is it at Millegan (14 mi SE)?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds at Millegan (14 mi SE), 4.0 kWh per square metre a day. July is the sunniest month (85%) and December the cloudiest (64%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 73% | 1.7 |
| February | 76% | 2.8 |
| March | 72% | 3.9 |
| April | 68% | 4.8 |
| May | 69% | 5.7 |
| June | 74% | 6.5 |
| July | 85% | 7.2 |
| August | 84% | 6.0 |
| September | 78% | 4.4 |
| October | 71% | 2.8 |
| November | 66% | 1.7 |
| December | 64% | 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 many heating and cooling degree days does Millegan (14 mi SE) record?
A normal year at Millegan (14 mi SE) brings 8,836 heating degree days, 64% more than the median U.S. place (5,373), and 95 cooling degree days, 90% fewer than the median (908). Nine months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,232 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,325 | 0 |
| February | 1,163 | 0 |
| March | 1,026 | 0 |
| April | 780 | 0 |
| May | 538 | 0 |
| June | 292 | 7 |
| July | 102 | 49 |
| August | 122 | 35 |
| September | 355 | 4 |
| October | 733 | 0 |
| November | 1,056 | 0 |
| December | 1,344 | 0 |
| Year (annual) | 8,836 | 95 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00245712. 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.
Have recent years at Millegan (14 mi SE) been warmer than normal?
2022 averaged 39.1°F, 1.8°F below the 1991-2020 normal of 40.9°F.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2022 | 39.1°F | −1.8°F | 12.40 | 11.5 |
Source: observed years: ACIS, station USC00245712. A year counts only with all twelve months complete.
How does Millegan (14 mi SE)'s climate compare?
Millegan (14 mi SE) is warmer than 19 of the 141 places with their own NOAA record in Montana, and wetter than 115. Across the 7,247 U.S. stations with normals, its annual mean of 40.9°F is warmer than 7%.
In the Köppen classification computed from these normals, Millegan (14 mi SE) is Dfb: continental, no dry season, warm summer. 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 Millegan (14 mi SE)'s climate
What is the coldest month at Millegan (14 mi SE)?
December, with a normal high of 32°F and a normal low of 11°F. The warmest is July (80°F by day, 46°F at night).
Does it snow at Millegan (14 mi SE)?
Yes: 149 inches in a normal year, falling on 44 days with 0.1 inch or more, the most in February (24.4 inches).
What is the rainiest month at Millegan (14 mi SE)?
June, with 3.61 in of precipitation in a normal year; the driest is December with 0.82 in.
What plant hardiness zone is Millegan (14 mi SE) in?
The USDA's 2023 map puts Millegan (14 mi SE) in zone 4b in ZIP code 59645, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −28°F (21 years, 1991-2020): zone 4a.
How late can frost come at Millegan (14 mi SE)?
In half of years the last 32°F night comes after June 11; in one year in ten it comes after July 3. Waiting until July 3 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Montana climateThe statewide normals and every place in the state
- Neihart, MT22 miles from this station, 43.7°F a year
- Adel, MT26 miles from this station, 41.5°F a year
- White Sulphur Springs, MT26 miles from this station, 42.1°F a year
- Cascade, MT35 miles from this station, 47.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made