Big Sky, MT Climate: Temperature & Rain by Month
Pulled from NOAA NCEI 1991–2020 normals →: climate measurements used in PlainClimate's documented score
30-year climate normals (1991-2020) from Big Sky's primary NOAA station, BIG SKY 2WNW.
The climate verdict for Big Sky
Big Sky, Montana has a mixed annual climate rather than one dominant extreme. Its NOAA normal shows an annual average of 38°F. July is the warmest month at 60°F and December the coldest at 18°F.
- 38°F
- annual average temperature (NOAA normal)
- 23.3"
- annual precipitation
Big Sky: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00240775 · Big Sky, MT 38°F mean · 23.3" precip
TEMP-COLD · RANK-COOL · PHOTO-FINISH · PRCP-DRY · SWING-MID · COMF-UNK · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COLD 38°F
- RANK-COOL #206
- PHOTO-FINISH ≈ Iliamna
- PRCP-DRY 23.3"
- SWING-MID 42°F
- COMF-UNK Comfort n/a
- LOAD-HEAT 9,955 HDD
- STN-1 USC00240775
- BOOK-FULL 5/6 fields
Nearest mean-temperature peer: Iliamna, AK (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every MT station list.
- Big Sky (this station) 38°F
- Cold Anchorage, AK 38°F
- Hot Twin Lakes Rsvr, CO 38°F
- Near Iliamna, AK 38°F
- Near Anchorage Upper…, AK 38°F
Big Sky sits in Montana, the #6 coldest U.S. state at 43.4°F statewide annual average - see all 50 coldest states ranked by NOAA normals
Climate Living Index · Big Sky
Big Sky: 14/100 · grade F
Big Sky publishes 3 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 3 missing weights rescale to 100.
PlainClimate-derived for Big Sky, not an official NOAA rating. Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Precipitation balance | 23.3 in · 11.7 from 35 in | 59/100 · C |
| Annual temperature balance | 37.7°F · 29.8° from 67.5°F | 0/100 · F |
| Normal heat + freeze calendar | 243 calendar days | 0/100 · F |
Big Sky · 2026-08-04 · NOAA NCEI Climate Normals · method .
Big Sky is a continental Köppen climate: Dfb
Coldest-month mean 18.0°F and warmest-month mean 59.5°F place this station in continental, no dry season, warm summer climates (Dfb). Class Dfb is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: continental, specifically continental, no dry season, warm summer.
- Köppen code
- Dfb
- Group
- Continental
- Warmest month
- 59.5°F
- Coldest month
- 18.0°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Big Sky sits across the climate record
Three NOAA fields for Big Sky's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 97%
- Among 6,861 stations, Big Sky sits in the cooler third of annual means.
- Annual precipitation
- 32nd percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- 42nd percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 30°F (-1°C) | 9°F (-13°C) | 19°F (-7°C) | 1.8" | 31.0 | 0.0 |
| February | 34°F (1°C) | 9°F (-13°C) | 22°F (-6°C) | 1.5" | 27.9 | 0.0 |
| March | 42°F (6°C) | 17°F (-9°C) | 29°F (-1°C) | 1.9" | 30.5 | 0.0 |
| April | 48°F (9°C) | 23°F (-5°C) | 35°F (2°C) | 2.4" | 28.9 | 0.0 |
| May | 58°F (15°C) | 30°F (-1°C) | 44°F (7°C) | 2.8" | 22.3 | 0.0 |
| June | 67°F (19°C) | 36°F (2°C) | 51°F (11°C) | 3.2" | 9.6 | 0.0 |
| July | 78°F (25°C) | 41°F (5°C) | 60°F (15°C) | 1.3" | 1.7 | 1.0 |
| August | 77°F (25°C) | 39°F (4°C) | 58°F (14°C) | 1.6" | 2.6 | 0.3 |
| September | 68°F (20°C) | 33°F (1°C) | 51°F (10°C) | 1.7" | 15.2 | 0.0 |
| October | 53°F (12°C) | 25°F (-4°C) | 39°F (4°C) | 1.8" | 27.4 | 0.0 |
| November | 37°F (3°C) | 16°F (-9°C) | 26°F (-3°C) | 1.6" | 29.4 | 0.0 |
| December | 28°F (-2°C) | 9°F (-13°C) | 18°F (-8°C) | 1.7" | 31.0 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 80°F around July 25, short of 90°F on every date, while 243 dates carry a normal low at or below freezing, the coldest 8°F near December 19.
The freezing stretch
The normal low stays at or below 32°F into May 22, then returns to freezing around September 23, covering 243 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is June 1, when 51% of years recorded at least a hundredth of an inch. The driest is October 1 at 30%. Summed across the calendar, that is about 141 wet dates a year.
The widest day
August 6 carries the biggest normal gap between afternoon and dawn, 38°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Big Sky.
Where Big Sky Stands Nationally
Winters bite deep and often: the normal nightly low dips to freezing or below on around 243 nights a year, placing this among the most frost-prone tenth of ranked stations.
Day-to-night contrast is extreme by national standards — the widest normal daily swing reaches about 38°F, sharper than nine in ten ranked stations see.
Big Sky earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall
12.6 days with precipitation
11.5 days with precipitation
11.5 days with precipitation
11.5 days with precipitation
13.4 days with precipitation
14.4 days with precipitation
10.2 days with precipitation
11.2 days with precipitation
9.6 days with precipitation
9.6 days with precipitation
11.1 days with precipitation
13.7 days with precipitation
Big Sky spreads its precipitation across the year
Neither half of the year dominates here: June through August take 26% of the annual total and December through February 22%, with neither reaching the 35% that would mark a distinct wet season. Big Sky has no dry season to plan around, though it does carry a 41.5°F seasonal spread.
The gap between the wettest and driest month still matters: June averages 3.2" and July 1.3". The three wettest months together take 36% of the year, against the 25% a perfectly flat distribution would give them.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.
Rain reaches Big Sky in small, frequent amounts
Big Sky records about 140 days with measurable precipitation a year and 23.3" in total, which works out to roughly 0.17 inches on an average wet day. Precipitation on 38% of all days, arriving that lightly, is the damp many-grey-days pattern rather than the storm-driven one.
Places in this band read as wetter than their annual totals suggest, because what people notice is the number of overcast days, not the depth in the gauge.
- Most wet days: June, about 14 of them.
- Fewest: September, about 10.
- Average depth per wet day: 0.17 inches.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year and say nothing about the heaviest single storm on record.
Frost Dates & Growing Season
First Fall Freeze
N/A
50% probability date
Last Spring Freeze
N/A
50% probability date
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
9,955
Higher = more heating needed
Cooling Degree Days
11
Higher = more cooling needed
Warmest Month
July
Coldest Month
December
Nationwide similar cities
Other rankable U.S. places outside MT closest to Big Sky on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (38°F here).
- Blackduck, MN 38°F · 0.0°F off
- Goodridge, MN 38°F · 0.0°F off
- Gunnison, CO 38°F · 0.0°F off
- Iliamna, AK 38°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (23.3" here), excluding temperature-peer places.
- Jayton, TX 23.3" · 0.0" off
- Portola, CA 23.3" · 0.0" off
- Eustis, NE 23.4" · 0.0" off
- Ballinger, TX 23.4" · 0.1" off
Data-derived climate profile
How Big Sky's climate pattern fits together
heating led · moderate · mid swing
Big Sky's energy balance leans toward cold weather: 9,955 annual heating degree days against 11 for cooling. Its 41.5°F seasonal range still makes the monthly rows more useful than the annual average alone.
A frost-free growing-season length is not available for Big Sky. That missing field is kept separate from the observed temperature and precipitation record rather than filled from a regional estimate.
July and December mark the typical warm and cold ends of the calendar in Big Sky's middle-range seasonal profile. The measured spread is 41.5°F. The annual average is 38°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Big Sky's 23.3 inches of annual precipitation falls in PlainClimate's middle band, so “wet” or “dry” is not the leading description. Snowfall is not added to the interpretation because its annual value is missing. Temperature balance and the calendar distribution carry more information than the annual moisture label alone.
These labels group NOAA 1991-2020 normals from Big Sky's primary station, so the winter figures are a thirty-year average and not a floor: a single hard season can run well below them. Treat each band as a descriptive range for Big Sky, not an official NOAA class or a year-ahead forecast.
Questions about Big Sky's climate
How much rain does Big Sky get? ▼
How cold does Big Sky get in winter? ▼
How much energy does heating and cooling require in Big Sky? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Big Sky's primary station: BIG SKY 2WNW (USC00240775). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as a census-designated place (GEOID 3006325), not an incorporated municipality. Match rule for Big Sky: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Big Sky comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.