Hamilton, MT Climate: Temperature & Rain by Month
Explore NOAA NCEI's 1991–2020 climate normals → and a clearly labeled PlainClimate comfort calculation
30-year climate normals (1991-2020) from Hamilton's primary NOAA station, HAMILTON.
The climate verdict for Hamilton
Dryness leads the climate profile for Hamilton, Montana, with 13.6 inches of precipitation a year. NOAA records an annual average of 45°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.
- 45°F
- average temperature, NOAA 1991-2020 normal
- 40/100
- comfort score, above 6% of station-mapped location scores
- 13.6"
- yearly precipitation total
- 124 days
- growing season, frost-free days
Hamilton: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00243885 · Hamilton, MT 45°F mean · 13.6" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-DRY · SWING-MID · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 45°F
- RANK-COOL #1,235
- PHOTO-FINISH ≈ Walton
- PRCP-DRY 13.6"
- SWING-MID 41°F
- COMF-LOW 40/100
- LOAD-HEAT 7,551 HDD
- STN-1 USC00243885
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Walton, NY (+ 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.
- Hamilton (this station) 45°F
- Hot Wapiti, WY 45°F
- Near Walton, NY 45°F
- Near Townsend, MT 45°F
- Near Wellsville, NY 45°F
Hamilton 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 · Hamilton
Hamilton: 18/100 · grade F
Hamilton publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Hamilton, not an official NOAA rating. Rankings still use Comfort Score 40/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Precipitation balance | 13.6 in · 21.4 from 35 in | 23/100 · F |
| Annual temperature balance | 44.8°F · 22.7° from 67.5°F | 19/100 · F |
| Normal heat + freeze calendar | 194 calendar days | 17/100 · F |
| Frost-free season | 124 days/year | 9/100 · F |
Hamilton · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Hamilton is a continental Köppen climate: Dfb
Coldest-month mean 25.7°F and warmest-month mean 66.8°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
- 66.8°F
- Coldest month
- 25.7°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 Hamilton sits across the climate record
Three NOAA fields for Hamilton's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 82%
- Among 6,861 stations, Hamilton sits in the cooler third of annual means.
- Annual precipitation
- Drier than 86%
- Hamilton's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- 40th percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
How Hamilton compares across U.S. station-mapped locations
Hamilton'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
Hamilton's measured station temperature trend
MethodologyAcross 77 complete annual observations from 1904 to 2021, HAMILTON changed little at a fitted rate of 0.00°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Hamilton primary station fitted change +0.00 °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 | 35°F (2°C) | 19°F (-7°C) | 27°F (-3°C) | 1.0" | 27.7 | 0.0 |
| February | 39°F (4°C) | 20°F (-7°C) | 29°F (-1°C) | 1.2" | 25.9 | 0.0 |
| March | 49°F (9°C) | 25°F (-4°C) | 37°F (3°C) | 1.0" | 25.7 | 0.0 |
| April | 56°F (13°C) | 31°F (-1°C) | 43°F (6°C) | 1.1" | 16.1 | 0.0 |
| May | 66°F (19°C) | 38°F (3°C) | 52°F (11°C) | 1.5" | 4.9 | 0.3 |
| June | 73°F (23°C) | 45°F (7°C) | 59°F (15°C) | 1.6" | 0.2 | 1.8 |
| July | 84°F (29°C) | 50°F (10°C) | 67°F (19°C) | 0.8" | 0.0 | 10.5 |
| August | 82°F (28°C) | 48°F (9°C) | 65°F (18°C) | 0.8" | 0.0 | 8.8 |
| September | 72°F (22°C) | 40°F (5°C) | 56°F (13°C) | 0.8" | 2.1 | 1.0 |
| October | 57°F (14°C) | 31°F (-1°C) | 44°F (7°C) | 0.9" | 16.5 | 0.0 |
| November | 43°F (6°C) | 23°F (-5°C) | 33°F (0°C) | 1.4" | 25.0 | 0.0 |
| December | 34°F (1°C) | 18°F (-8°C) | 26°F (-4°C) | 1.3" | 28.3 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 87°F around July 27, short of 90°F on every date, while 194 dates carry a normal low at or below freezing, the coldest 17°F near December 19.
The freezing stretch
The normal low stays at or below 32°F into April 23, then returns to freezing around October 13, covering 194 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 May 27, when 37% of years recorded at least a hundredth of an inch. The driest is July 24 at 21%. Summed across the calendar, that is about 108 wet dates a year.
The widest day
July 28 carries the biggest normal gap between afternoon and dawn, 36°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Hamilton.
Where Hamilton Stands Nationally
Freezing is routine here by normals standards — the normal low reaches 32°F or colder on about 194 nights a year, more than most ranked stations.
A drier-than-most normal water year — around 14 inches, below what four out of five ranked stations collect.
Hamilton earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall
9.2 days with precipitation
8.7 days with precipitation
10.3 days with precipitation
9.4 days with precipitation
10.7 days with precipitation
9.7 days with precipitation
6.6 days with precipitation
7.0 days with precipitation
6.3 days with precipitation
8.7 days with precipitation
10.1 days with precipitation
10.4 days with precipitation
Hamilton spreads its precipitation across the year
Neither half of the year dominates here: June through August take 24% of the annual total and December through February 26%, with neither reaching the 35% that would mark a distinct wet season. Hamilton has no dry season to plan around, though it does carry a 41.1°F seasonal spread.
The gap between the wettest and driest month still matters: June averages 1.6" and August 0.8". The three wettest months together take 34% 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.
Hamilton is dry, and what does fall arrives gently
Only about 107 days a year record measurable precipitation here, 29% of the calendar, and they carry 13.6" between them. At roughly 0.13 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 May at about 11 wet days; the driest is September at about 6.
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 22
50% probability date
Last Spring Freeze
May 21
50% probability date
Growing Season
124 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
7,551
Higher = more heating needed
Cooling Degree Days
216
Higher = more cooling needed
Warmest Month
July
Coldest Month
December
Nationwide similar cities
Other rankable U.S. places outside MT closest to Hamilton 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 (45°F here).
- Dannemora, NY 45°F · 0.0°F off
- Estherville, IA 45°F · 0.0°F off
- Harrison, NE 45°F · 0.0°F off
- Koosharem, UT 45°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (13.6" here), excluding temperature-peer places.
- Westcliffe, CO 13.6" · 0.0" off
- Las Animas, CO 13.6" · 0.0" off
- Estancia, NM 13.6" · 0.0" off
- Maeser, UT 13.6" · 0.0" off
Scarce-water calendar
Where Hamilton's limited precipitation lands
heating led · dry · mid swing
Hamilton's energy balance leans toward cold weather: 7,551 annual heating degree days against 216 for cooling. Its 41.1°F seasonal range still makes the monthly rows more useful than the annual average alone.
Only about 124 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 December mark the typical warm and cold ends of the calendar in Hamilton's middle-range seasonal profile. The measured spread is 41.1°F. The annual average is 45°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Hamilton's cold-season load does not imply a wet climate. Annual precipitation is 13.6 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.
Hamilton wettest normal
June
June concentrates the scarce annual total (13.6 inches).
Hamilton driest normal
August
August is typically driest; arid stations are defined by when water is absent, not by a four-season grid.
Questions about Hamilton's climate
How dry is Hamilton? ▼
How cold does Hamilton get in winter? ▼
How much energy does heating and cooling require in Hamilton? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Hamilton's primary station: HAMILTON (USC00243885). 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 3033775). Match rule for Hamilton: 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 Hamilton 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.