Bynum, MT Climate: Temperature & Rain by Month
Average temperature and precipitation from NOAA NCEI 1991–2020 normals →, with a derived climate comfort score
30-year climate normals (1991-2020) from Bynum's primary NOAA station, BYNUM 4 SSE.
The climate verdict for Bynum
Dryness leads the climate profile for Bynum, Montana, with 15.3 inches of precipitation a year. NOAA records an annual average of 44°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.
- 44°F
- yearly average temperature, NOAA normal
- 40/100
- comfort score, above 6% of station-mapped location scores
- 15.3"
- precipitation, annual total
- 134 days
- frost-free days per growing season
Bynum: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00241342 · Bynum, MT 44°F mean · 15.3" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-DRY · SWING-MID · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 44°F
- RANK-COOL #892
- PHOTO-FINISH ≈ Story
- PRCP-DRY 15.3"
- SWING-MID 41°F
- COMF-LOW 40/100
- LOAD-HEAT 8,040 HDD
- STN-1 USC00241342
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Story, WY (+ 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.
- Bynum (this station) 44°F
- Hot Diversion Dam, WY 44°F
- Near Story, WY 44°F
- Cold Ashton, ID 43°F
- Near Red Lodge, MT 43°F
Bynum 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 · Bynum
Bynum: 18/100 · grade F
Bynum publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Bynum, not an official NOAA rating. Rankings still use Comfort Score 40/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Precipitation balance | 15.3 in · 19.7 from 35 in | 30/100 · F |
| Normal heat + freeze calendar | 194 calendar days | 17/100 · F |
| Frost-free season | 134 days/year | 15/100 · F |
| Annual temperature balance | 43.5°F · 24.0° from 67.5°F | 14/100 · F |
Bynum · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Bynum'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
- 66.2°F
- Coldest month
- 25.2°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 Bynum sits across the climate record
Three NOAA fields for Bynum's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 87%
- Among 6,861 stations, Bynum sits in the cooler third of annual means.
- Annual precipitation
- Drier than 82%
- Bynum'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 Bynum compares across U.S. station-mapped locations
Bynum'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 | 36°F (2°C) | 14°F (-10°C) | 25°F (-4°C) | 0.6" | 27.2 | 0.0 |
| February | 36°F (2°C) | 15°F (-9°C) | 26°F (-4°C) | 0.4" | 25.8 | 0.0 |
| March | 44°F (6°C) | 21°F (-6°C) | 32°F (0°C) | 1.1" | 26.5 | 0.0 |
| April | 51°F (11°C) | 29°F (-2°C) | 40°F (5°C) | 2.1" | 17.8 | 0.0 |
| May | 62°F (16°C) | 39°F (4°C) | 50°F (10°C) | 2.6" | 4.4 | 0.0 |
| June | 71°F (21°C) | 47°F (8°C) | 59°F (15°C) | 2.5" | 0.0 | 0.6 |
| July | 80°F (27°C) | 52°F (11°C) | 66°F (19°C) | 1.6" | 0.0 | 4.3 |
| August | 79°F (26°C) | 51°F (11°C) | 65°F (19°C) | 1.3" | 0.0 | 3.4 |
| September | 70°F (21°C) | 43°F (6°C) | 56°F (14°C) | 1.2" | 1.6 | 0.3 |
| October | 55°F (13°C) | 32°F (0°C) | 44°F (6°C) | 1.0" | 15.1 | 0.0 |
| November | 43°F (6°C) | 23°F (-5°C) | 33°F (1°C) | 0.5" | 23.0 | 0.0 |
| December | 35°F (1°C) | 16°F (-9°C) | 25°F (-4°C) | 0.4" | 27.7 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 83°F around July 28, short of 90°F on every date, while 194 dates carry a normal low at or below freezing, the coldest 14°F near January 3.
The freezing stretch
The normal low stays at or below 32°F into April 26, then returns to freezing around October 16, 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.
The widest day
July 22 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 Bynum.
Where Bynum 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 15 inches, below what four out of five ranked stations collect.
Bynum earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall
Bynum spreads its precipitation across the year
Neither half of the year dominates here: June through August take 35% of the annual total and December through February 10%, with neither reaching the 35% that would mark a distinct wet season. Bynum has no dry season to plan around, though it does carry a 41°F seasonal spread.
The gap between the wettest and driest month still matters: May averages 2.6" and February 0.4". The three wettest months together take 47% 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.
Frost Dates & Growing Season
First Fall Freeze
September 27
50% probability date
Last Spring Freeze
May 16
50% probability date
Growing Season
134 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
8,040
Higher = more heating needed
Cooling Degree Days
221
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside MT closest to Bynum 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 (44°F here).
- Alpena, MI 44°F · 0.0°F off
- Amery, WI 44°F · 0.0°F off
- Blanca, CO 44°F · 0.0°F off
- Cross Village, MI 44°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (15.3" here), excluding temperature-peer places.
- Carpenter, WY 15.3" · 0.0" off
- Fortuna, ND 15.3" · 0.0" off
- Hugo, CO 15.3" · 0.0" off
- Elgin, AZ 15.4" · 0.0" off
Data-derived climate profile
How Bynum's climate pattern fits together
heating led · dry · mid swing
Bynum's energy balance leans toward cold weather: 8,040 annual heating degree days against 221 for cooling. Its 41.0°F seasonal range still makes the monthly rows more useful than the annual average alone.
Only about 134 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 Bynum's middle-range seasonal profile. The measured spread is 41.0°F. The annual average is 44°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Bynum's cold-season load does not imply a wet climate. Annual precipitation is 15.3 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.
These labels group NOAA 1991-2020 normals from Bynum'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 Bynum, not an official NOAA class or a year-ahead forecast.
Questions about Bynum's climate
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Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Bynum's primary station: BYNUM 4 SSE (USC00241342). 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 3011500), not an incorporated municipality. Match rule for Bynum: 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 Bynum 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.