Shelby, Montana climate: Normal weather by month, frost dates and records
Shelby's normal year runs from 6°F January nights to 82°F July afternoons, with 12.1 inches of precipitation and 39 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 5.7°C, January lows of −14°C, July highs of 28°C, 308 mm of precipitation a year.
- NOAA stationShelby
- Station IDUSC00247500
- Location48.51°N 111.86°W
- Elevation3,325 ft (1,014 m)
- Population3,273
On October 22, the normal high in Shelby is 53°F and the normal low 26°F, and the chance of measurable rain or snow is 17%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Shelby.
- Jan 31° 6°
- Feb 35° 10°
- Mar 44° 18°
- Apr 54° 28°
- May 64° 38°
- Jun 73° 46°
- Jul 82° 52°
- Aug 82° 49°
- Sep 71° 41°
- Oct 56° 29°
- Nov 42° 18°
- Dec 33° 9°
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 Shelby each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 6°F. The most precipitation falls in June (2.85 in), the least in February (0.36 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 6°F | 18.8°F | 0.46 | 7.3 | 5 | <1 | 29 | 8 h 40 min |
| February | 35°F | 10°F | 22.6°F | 0.36 | 5.8 | 5 | <1 | 27 | 10 h 10 min |
| March | 44°F | 18°F | 31.2°F | 0.63 | 6.9 | 6 | <1 | 28 | 11 h 50 min |
| April | 54°F | 28°F | 41.3°F | 1.34 | 4.1 | 7 | <1 | 20 | 13 h 40 min |
| May | 64°F | 38°F | 51.2°F | 1.77 | 1.9 | 9 | <1 | 8 | 15 h 10 min |
| June | 73°F | 46°F | 59.3°F | 2.85 | 0.0 | 11 | 1 | <1 | 16 h 10 min |
| July | 82°F | 52°F | 66.8°F | 1.14 | 0.0 | 6 | 8 | <1 | 15 h 50 min |
| August | 82°F | 49°F | 65.8°F | 0.85 | 0.0 | 6 | 8 | <1 | 14 h 20 min |
| September | 71°F | 41°F | 55.7°F | 1.01 | 0.5 | 6 | 2 | 4 | 12 h 40 min |
| October | 56°F | 29°F | 42.6°F | 0.74 | 1.4 | 5 | <1 | 19 | 11 h |
| November | 42°F | 18°F | 29.8°F | 0.52 | 5.5 | 5 | <1 | 26 | 9 h 20 min |
| December | 33°F | 9°F | 21.1°F | 0.46 | 5.5 | 5 | <1 | 29 | 8 h 20 min |
| Year (annual) | 56°F | 29°F | 42.2°F | 12.13 | 38.9 | 77 | 18 | 190 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −14°C | −7.3°C | 12 mm | 19 cm |
| February | 2°C | −12°C | −5.2°C | 9 mm | 15 cm |
| March | 7°C | −8°C | −0.4°C | 16 mm | 18 cm |
| April | 12°C | −2°C | 5.2°C | 34 mm | 10 cm |
| May | 18°C | 3°C | 10.7°C | 45 mm | 5 cm |
| June | 23°C | 8°C | 15.2°C | 72 mm | 0 cm |
| July | 28°C | 11°C | 19.3°C | 29 mm | 0 cm |
| August | 28°C | 10°C | 18.8°C | 22 mm | 0 cm |
| September | 22°C | 5°C | 13.2°C | 26 mm | 1 cm |
| October | 13°C | −2°C | 5.9°C | 19 mm | 4 cm |
| November | 6°C | −8°C | −1.2°C | 13 mm | 14 cm |
| December | 1°C | −13°C | −6.1°C | 12 mm | 14 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00247500; 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 Shelby?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, August 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 USC00247500.
When is the last frost in Shelby?
In Shelby, the last spring frost (32°F) comes after May 23 in half of years and after June 6 in one year in ten; the first autumn frost comes before September 16 in half of years and before September 3 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 231 year in 10 after June 6; 9 in 10 after May 11
- First autumn frost, half of years before
- September 161 year in 10 before September 3; 9 in 10 before September 28
NOAA puts the median frost-free season at 115 days, and the season without a hard freeze (28°F) at 138 days.
A hard freeze (28°F) comes after May 10 in half of springs and before September 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Shelby in zone 4a in ZIP code 59474, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Shelby's NOAA station is in zone 4a: the coldest night of a typical year reaches −29°F (24 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 USC00247500; 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 Shelby?
In a normal year in Shelby, 18 days a year reach 90°F (1 of them 100°F or more), 190 nights fall to 32°F or colder and 77 days bring measurable precipitation.
- Days at 90°F or more
- 18a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 190a normal year
- Days that stay below freezing
- 46high of 32°F or less
- Days with 0.01 inch of precipitation
- 77a normal year
- Days with 1 inch of snow or more
- 13a normal year
The highest temperature in this station's record (since 1950) is 103°F, on August 11, 2018; the lowest is −44°F, on January 20, 1954.
The wettest calendar year on that record is 2010, with 16.83 in; the snowiest season is 2008–09, with 68.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00247500; records: ACIS (NOAA Regional Climate Centers), station USC00247500. Records use complete months only; a month missing more than three days is left out.
How sunny is Shelby?
Over a year 76% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Shelby, 3.9 kWh per square metre a day. July is the sunniest month (87%) and December the cloudiest (62%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 67% | 1.3 |
| February | 69% | 2.3 |
| March | 70% | 3.5 |
| April | 72% | 4.9 |
| May | 73% | 5.9 |
| June | 78% | 6.6 |
| July | 87% | 7.1 |
| August | 85% | 5.8 |
| September | 79% | 4.2 |
| October | 73% | 2.6 |
| November | 67% | 1.5 |
| December | 62% | 1.0 |
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 Shelby need?
A normal year in Shelby brings 8,532 heating degree days, 59% more than the median U.S. place (5,373), and 242 cooling degree days, 73% 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 1,697 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,434 | 0 |
| February | 1,187 | 0 |
| March | 1,049 | 0 |
| April | 711 | 0 |
| May | 431 | 4 |
| June | 190 | 19 |
| July | 52 | 109 |
| August | 74 | 97 |
| September | 292 | 12 |
| October | 695 | 0 |
| November | 1,056 | 0 |
| December | 1,361 | 0 |
| Year (annual) | 8,532 | 242 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00247500. 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 Shelby been warmer than normal lately?
2025 averaged 44.2°F, 2.0°F above the 1991-2020 normal of 42.2°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 44.1°F | +1.9°F | 10.91 | 27.6 |
| 2022 | 43.0°F | +0.8°F | 10.60 | 33.1 |
| 2023 | 45.5°F | +3.3°F | 8.99 | 24.6 |
| 2024 | 44.4°F | +2.2°F | 12.13 | 23.2 |
| 2025 | 44.2°F | +2.0°F | 11.80 | 28.4 |
Source: observed years: ACIS, station USC00247500. A year counts only with all twelve months complete.
How does Shelby's climate compare?
Shelby is warmer than 34 of the other 140 places with their own NOAA record in Montana, and wetter than 17. Across the 7,247 U.S. stations with normals, its annual mean of 42.2°F is warmer than 10%.
In the Köppen classification computed from these normals, Shelby 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.
Which places near Shelby share this climate record?
Camrose Colony has no NOAA station with 1991-2020 normals of its own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Camrose Colony, MT92 people · 18 mi SE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Shelby's climate
What is the coldest month in Shelby?
January, with a normal high of 31°F and a normal low of 6°F. The warmest is July (82°F by day, 52°F at night).
Does it snow in Shelby?
Yes: 39 inches in a normal year, falling on 21 days with 0.1 inch or more, the most in January (7.3 inches).
What is the rainiest month in Shelby?
June, with 2.85 in of precipitation in a normal year; the driest is February with 0.36 in.
What plant hardiness zone is Shelby in?
The USDA's 2023 map puts Shelby in zone 4a in ZIP code 59474, the nearest ZIP area. By the same method at Shelby's NOAA station, the coldest night of a typical year reaches −29°F (24 years, 1991-2020): zone 4a.
How late can frost come in Shelby?
In half of years the last 32°F night comes after May 23; in one year in ten it comes after June 6. Waiting until June 6 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Montana climateThe statewide normals and every place in the state
- Dunkirk (19 mi NNE), MT22 miles from this station, 41.0°F a year
- Valier, MT23 miles from this station, 44.1°F a year
- Conrad, MT24 miles from this station, 43.7°F a year
- Cut Bank, MT25 miles from this station, 41.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made