St Marie, MT Climate: Temperature & Rain by Month
Temperature and precipitation from NOAA NCEI 1991–2020 normals →, plus PlainClimate's derived comfort score
30-year climate normals (1991-2020) from St Marie's primary NOAA station, ST MARIE.
The climate verdict for St Marie
Winter sets the terms in St Marie, Montana. A pronounced 55.6°F seasonal swing and heating demand above twice the cooling total frame an annual average of 43°F. At 40/100 (moderate) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 6% of scores.
- 43°F
- annual average temperature (NOAA normal)
- 40/100
- comfort score, above 6% of station-mapped location scores
- 11.8"
- annual precipitation
- 137 days
- frost-free days per growing season
St Marie: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USW00094010 · St Marie, MT 43°F mean · 11.8" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-ARID · SWING-WIDE · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 43°F
- RANK-COOL #823
- PHOTO-FINISH ≈ Milbank
- PRCP-ARID 11.8"
- SWING-WIDE 56°F
- COMF-LOW 40/100
- LOAD-HEAT 8,452 HDD
- STN-1 USW00094010
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Milbank, SD (+ 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.
- St Marie (this station) 43°F
- Hot Lake Wilson, MN 43°F
- Near Milbank, SD 43°F
- Near Rice Lake, WI 43°F
- Near Almont, ND 43°F
St Marie 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 · St Marie
St Marie: 18/100 · grade F
St Marie publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for St Marie, not an official NOAA rating. Rankings still use Comfort Score 40/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 184 calendar days | 23/100 · F |
| Precipitation balance | 11.8 in · 23.2 from 35 in | 18/100 · F |
| Frost-free season | 137 days/year | 17/100 · F |
| Annual temperature balance | 43.0°F · 24.5° from 67.5°F | 13/100 · F |
St Marie · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
St Marie's normals sit in a dry climate class: BSk
Precipitation is low relative to temperature but above true desert thresholds: cold semi-arid steppe (BSk). Class BSk is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: dry (arid or semi-arid), specifically cold semi-arid steppe.
- Köppen code
- BSk
- Group
- Dry (arid or semi-arid)
- Warmest month
- 70.6°F
- Coldest month
- 15.0°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 St Marie sits across the climate record
Three NOAA fields for St Marie's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 88%
- Among 6,861 stations, St Marie sits in the cooler third of annual means.
- Annual precipitation
- Drier than 90%
- St Marie's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- Wider than 93%
- Warmest-to-coldest month gap for St Marie is large versus 6,861 complete station-years.
How St Marie compares across U.S. station-mapped locations
St Marie's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
40 6th percentile score exceeds 6% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). This entry sits in this band.
- 50–60: 1,329 station-mapped locations (21%). Above this entry.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 24°F (-4°C) | 6°F (-15°C) | 15°F (-9°C) | 0.3" | 30.4 | 0.0 |
| February | 28°F (-2°C) | 9°F (-13°C) | 18°F (-8°C) | 0.2" | 27.5 | 0.0 |
| March | 41°F (5°C) | 20°F (-7°C) | 31°F (-1°C) | 0.2" | 27.2 | 0.0 |
| April | 56°F (13°C) | 31°F (-1°C) | 44°F (6°C) | 0.8" | 16.5 | 0.0 |
| May | 67°F (19°C) | 41°F (5°C) | 54°F (12°C) | 1.9" | 5.1 | 0.0 |
| June | 75°F (24°C) | 51°F (10°C) | 63°F (17°C) | 3.1" | 0.1 | 1.1 |
| July | 85°F (29°C) | 57°F (14°C) | 71°F (21°C) | 1.6" | 0.0 | 9.1 |
| August | 84°F (29°C) | 56°F (13°C) | 70°F (21°C) | 1.3" | 0.0 | 8.4 |
| September | 73°F (23°C) | 46°F (8°C) | 59°F (15°C) | 1.0" | 1.3 | 1.8 |
| October | 57°F (14°C) | 33°F (1°C) | 45°F (7°C) | 0.9" | 14.3 | 0.0 |
| November | 39°F (4°C) | 20°F (-6°C) | 30°F (-1°C) | 0.3" | 25.6 | 0.0 |
| December | 27°F (-3°C) | 9°F (-13°C) | 18°F (-8°C) | 0.2" | 30.6 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 87°F around July 29, short of 90°F on every date, while 184 dates carry a normal low at or below freezing, the coldest 6°F near January 13.
The freezing stretch
The normal low stays at or below 32°F into April 19, then returns to freezing around October 19, covering 184 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 10, when 38% of years recorded at least a hundredth of an inch. The driest is January 31 at 9%. Summed across the calendar, that is about 66 wet dates a year.
The widest day
August 2 carries the biggest normal gap between afternoon and dawn, 29°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for St Marie.
Where St Marie Stands Nationally
Aridity defines the water calendar: about 12 inches in a normal year lands this among the driest tenth of ranked stations.
Freezing is routine here by normals standards — the normal low reaches 32°F or colder on about 184 nights a year, more than most ranked stations.
St Marie earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall
3.4 days with precipitation
2.9 days with precipitation
3.1 days with precipitation
5.5 days with precipitation
8.8 days with precipitation
11.4 days with precipitation
7.4 days with precipitation
6.3 days with precipitation
5.7 days with precipitation
5.6 days with precipitation
3.3 days with precipitation
3.4 days with precipitation
St Marie runs a summer-peaked wet season
51% of St Marie's yearly precipitation falls in June, July and August alone, against the 25% an evenly spread year would give those three months. The wettest month is June at 3.1", on a wide 55.6°F gap between its warmest and coldest month. Warm-season convection and, across the Southwest, the North American monsoon produce this shape: rain arrives in short heavy bursts during the hottest part of the year rather than as long cool-season soaking.
- Wettest three months: June, May, July, taking 56% of the annual total between them.
- Driest month: December at 0.2".
- Winter share: 5% falls in December, January and February.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A summer-peaked label means the June-August share reaches 35%; it describes timing across an average year, not any single season, and says nothing about how heavy an individual storm can be.
St Marie is dry, and what does fall arrives gently
Only about 67 days a year record measurable precipitation here, 18% of the calendar, and they carry 11.8" between them. At roughly 0.18 inches on an average wet day, this is not the damp drizzle of a marine climate; it is an arid record in which precipitation is both uncommon and light when it appears.
The wettest month by count is June at about 11 wet days; the driest is February at about 3.
A low per-event average in a dry record is a statement about typical days only. Arid regions can still take a large share of a year's total from a single convective storm, which a normal cannot show.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, not the extremes within it.
Frost Dates & Growing Season
First Fall Freeze
September 27
50% probability date
Last Spring Freeze
May 13
50% probability date
Growing Season
137 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
8,452
Higher = more heating needed
Cooling Degree Days
487
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside MT closest to St Marie 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 (43°F here).
- Arco, ID 43°F · 0.0°F off
- Browns Valley, MN 43°F · 0.0°F off
- Estes Park, CO 43°F · 0.0°F off
- Fife Lake, MI 43°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (11.8" here), excluding temperature-peer places.
- Benson, AZ 11.8" · 0.0" off
- Hawthorne, CA 11.8" · 0.0" off
- Delta Junction, AK 11.8" · 0.0" off
- Flaming Gorge, UT 11.8" · 0.0" off
Scarce-water calendar
Where St Marie's limited precipitation lands
heating led · dry · high swing
Winter and seasonal range jointly define this record. St Marie logs 8,452 heating degree days, more than twice its 487 cooling total, while the typical coldest-to-warmest-month gap reaches 55.6°F. The annual mean therefore compresses two materially different seasons.
Only about 137 days are frost-free in a normal year. That short interval is consistent with the cold-season signal, but the measure does not predict the exact first or last freeze in any one year.
July and January mark the typical warm and cold ends of the calendar in this dry, high-range record. The gap is 55.6°F, so a single annual figure is especially lossy; the annual average is 43°f. Compare monthly temperature and precipitation together before drawing a seasonal conclusion about St Marie.
St Marie's cold-season load does not imply a wet climate. Annual precipitation is 11.8 inches, which places the station in PlainClimate's dry range. Snowfall is not added to the interpretation because its annual value is missing. The snowfall and rainfall fields should be read separately rather than inferred from temperature.
St Marie wettest normal
June
June concentrates the scarce annual total (11.8 inches).
St Marie driest normal
December
December is typically driest; arid stations are defined by when water is absent, not by a four-season grid.
Questions about St Marie's climate
How dry is St Marie? ▼
How cold does St Marie get in winter? ▼
How much energy does heating and cooling require in St Marie? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from St Marie's primary station: ST MARIE (USW00094010). 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 3065400), not an incorporated municipality. Match rule for St Marie: 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 St Marie 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.