Westby, 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 Westby's primary NOAA station, WESTBY.
The climate verdict for Westby
Winter sets the terms in Westby, Montana. A pronounced 58.6°F seasonal swing and heating demand above twice the cooling total frame an annual average of 39°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.
- 39°F
- yearly average temperature, NOAA normal
- 40/100
- comfort score, above 6% of station-mapped location scores
- 14.9"
- annual precipitation
- 126 days
- frost-free days per growing season
Westby: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00248777 · Westby, MT 39°F mean · 14.9" precip
TEMP-COLD · RANK-COOL · PHOTO-FINISH · PRCP-DRY · SWING-WIDE · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COLD 39°F
- RANK-COOL #274
- PHOTO-FINISH ≈ Esmond
- PRCP-DRY 14.9"
- SWING-WIDE 59°F
- COMF-LOW 40/100
- LOAD-HEAT 9,695 HDD
- STN-1 USC00248777
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Esmond, ND (+ 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.
- Westby (this station) 39°F
- Cold Fosston, MN 39°F
- Hot Tuttle, ND 39°F
- Near Esmond, ND 39°F
- Near Eveleth Wwtp, MN 39°F
Westby 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 · Westby
Westby: 12/100 · grade F
Westby publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Westby, not an official NOAA rating. Rankings still use Comfort Score 40/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Precipitation balance | 14.9 in · 20.1 from 35 in | 28/100 · F |
| Normal heat + freeze calendar | 203 calendar days | 12/100 · F |
| Frost-free season | 126 days/year | 10/100 · F |
| Annual temperature balance | 39.1°F · 28.4° from 67.5°F | 2/100 · F |
Westby · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Westby is a continental Köppen climate: Dfb
Coldest-month mean 8.7°F and warmest-month mean 67.3°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
- 67.3°F
- Coldest month
- 8.7°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 Westby sits across the climate record
Three NOAA fields for Westby's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 96%
- Among 6,861 stations, Westby sits in the cooler third of annual means.
- Annual precipitation
- Drier than 83%
- Westby's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- Wider than 96%
- Warmest-to-coldest month gap for Westby is large versus 6,861 complete station-years.
How Westby compares across U.S. station-mapped locations
Westby'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
Westby's measured station temperature trend
MethodologyAcross 44 complete annual observations from 1937 to 2025, WESTBY warmed at a fitted rate of 0.20°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Westby primary station fitted change +0.20 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 20°F (-7°C) | -2°F (-19°C) | 9°F (-13°C) | 0.4" | 31.0 | 0.0 |
| February | 24°F (-5°C) | 2°F (-17°C) | 13°F (-11°C) | 0.3" | 27.9 | 0.0 |
| March | 36°F (2°C) | 14°F (-10°C) | 25°F (-4°C) | 0.6" | 29.9 | 0.0 |
| April | 53°F (11°C) | 27°F (-3°C) | 40°F (4°C) | 1.0" | 21.7 | 0.0 |
| May | 65°F (19°C) | 40°F (4°C) | 52°F (11°C) | 2.2" | 6.6 | 0.1 |
| June | 73°F (23°C) | 50°F (10°C) | 62°F (16°C) | 3.1" | 0.1 | 0.8 |
| July | 80°F (27°C) | 55°F (13°C) | 67°F (20°C) | 2.5" | 0.0 | 3.1 |
| August | 80°F (27°C) | 52°F (11°C) | 66°F (19°C) | 1.6" | 0.0 | 4.3 |
| September | 70°F (21°C) | 41°F (5°C) | 55°F (13°C) | 1.3" | 4.2 | 1.3 |
| October | 54°F (12°C) | 29°F (-2°C) | 41°F (5°C) | 1.0" | 21.0 | 0.0 |
| November | 36°F (2°C) | 15°F (-10°C) | 25°F (-4°C) | 0.5" | 28.9 | 0.0 |
| December | 24°F (-5°C) | 4°F (-16°C) | 14°F (-10°C) | 0.5" | 30.9 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 82°F around July 30, short of 90°F on every date, while 203 dates carry a normal low at or below freezing, the coldest -3°F near January 17.
The freezing stretch
The normal low stays at or below 32°F into April 28, then returns to freezing around October 9, covering 203 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.
The widest day
September 3 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 Westby.
Where Westby Stands Nationally
Winters bite deep and often: the normal nightly low dips to freezing or below on around 203 nights a year, placing this among the most frost-prone tenth of ranked stations.
A drier-than-most normal water year — around 15 inches, below what four out of five ranked stations collect.
Westby earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall
Westby runs a summer-peaked wet season
49% of Westby'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 58.6°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, July, May, taking 52% of the annual total between them.
- Driest month: February at 0.3".
- Winter share: 8% 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.
Frost Dates & Growing Season
First Fall Freeze
September 21
50% probability date
Last Spring Freeze
May 18
50% probability date
Growing Season
126 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
9,695
Higher = more heating needed
Cooling Degree Days
286
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside MT closest to Westby 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 (39°F here).
- Alta, UT 39°F · 0.0°F off
- Divide, CO 39°F · 0.0°F off
- Esmond, ND 39°F · 0.0°F off
- Hallock, MN 39°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (14.9" here), excluding temperature-peer places.
- Laketown, UT 14.9" · 0.0" off
- Dillon, CO 14.9" · 0.0" off
- Kanab, UT 14.9" · 0.0" off
- Lamoille, NV 14.9" · 0.0" off
Scarce-water calendar
Where Westby's limited precipitation lands
heating led · dry · high swing
Winter and seasonal range jointly define this record. Westby logs 9,695 heating degree days, more than twice its 286 cooling total, while the typical coldest-to-warmest-month gap reaches 58.6°F. The annual mean therefore compresses two materially different seasons.
Only about 126 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 58.6°F, so a single annual figure is especially lossy; the annual average is 39°f. Compare monthly temperature and precipitation together before drawing a seasonal conclusion about Westby.
Westby's cold-season load does not imply a wet climate. Annual precipitation is 14.9 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.
Westby wettest normal
June
June concentrates the scarce annual total (14.9 inches).
Westby driest normal
February
February is typically driest; arid stations are defined by when water is absent, not by a four-season grid.
Questions about Westby's climate
How dry is Westby? ▼
How cold does Westby get in winter? ▼
How much energy does heating and cooling require in Westby? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Westby's primary station: WESTBY (USC00248777). 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 an incorporated place (GEOID 3078925). Match rule for Westby: 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 Westby 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.