Green Mt Dam, CO 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 Green Mt Dam's primary NOAA station, GREEN MT DAM.
The climate verdict for Green Mt Dam
Dryness leads the climate profile for Green Mt Dam, Colorado, with 16.5 inches of precipitation a year. NOAA records 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
- 16.5"
- yearly precipitation total
- 100 days
- frost-free days per growing season
Green Mt Dam: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00053592 · Green Mt Dam, CO 39°F mean · 16.5" 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 ≈ Lennep
- PRCP-DRY 16.5"
- SWING-WIDE 46°F
- COMF-LOW 40/100
- LOAD-HEAT 9,619 HDD
- STN-1 USC00053592
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Lennep, MT (+ 0.1 °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 CO station list.
- Green Mt Dam (this station) 39°F
- Hot Dillon, MT 39°F
- Near Lennep, MT 39°F
- Near Sunshine, WY 39°F
- Near Scofield-skylin…, UT 39°F
Climate Living Index · Green Mt Dam
Green Mt Dam: 7/100 · grade F
Green Mt Dam publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Green Mt Dam, not an official NOAA rating. Rankings still use Comfort Score 40/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Precipitation balance | 16.5 in · 18.5 from 35 in | 34/100 · F |
| Annual temperature balance | 38.6°F · 28.9° from 67.5°F | 1/100 · F |
| Normal heat + freeze calendar | 232 calendar days | 1/100 · F |
| Frost-free season | 100 days/year | 0/100 · F |
Green Mt Dam · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Green Mt Dam is a continental Köppen climate: Dfb
Coldest-month mean 15.7°F and warmest-month mean 61.6°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
- 61.6°F
- Coldest month
- 15.7°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 Green Mt Dam sits across the climate record
Three NOAA fields for Green Mt Dam'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, Green Mt Dam sits in the cooler third of annual means.
- Annual precipitation
- Drier than 79%
- Green Mt Dam's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- 63rd percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
How Green Mt Dam compares across U.S. station-mapped locations
Green Mt Dam'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 | 28°F (-2°C) | 4°F (-16°C) | 16°F (-9°C) | 1.1" | 31.0 | 0.0 |
| February | 33°F (0°C) | 7°F (-14°C) | 20°F (-7°C) | 1.1" | 28.0 | 0.0 |
| March | 42°F (6°C) | 15°F (-9°C) | 29°F (-2°C) | 1.2" | 30.8 | 0.0 |
| April | 51°F (10°C) | 24°F (-4°C) | 37°F (3°C) | 1.9" | 27.8 | 0.0 |
| May | 61°F (16°C) | 32°F (0°C) | 46°F (8°C) | 1.7" | 15.9 | 0.0 |
| June | 74°F (23°C) | 39°F (4°C) | 57°F (14°C) | 1.1" | 3.6 | 0.0 |
| July | 79°F (26°C) | 44°F (7°C) | 62°F (16°C) | 1.6" | 0.3 | 0.6 |
| August | 76°F (24°C) | 43°F (6°C) | 59°F (15°C) | 1.6" | 0.9 | 0.2 |
| September | 69°F (20°C) | 36°F (2°C) | 52°F (11°C) | 1.5" | 11.5 | 0.0 |
| October | 55°F (13°C) | 26°F (-3°C) | 41°F (5°C) | 1.4" | 25.2 | 0.0 |
| November | 40°F (4°C) | 16°F (-9°C) | 28°F (-2°C) | 1.1" | 29.5 | 0.0 |
| December | 29°F (-2°C) | 6°F (-14°C) | 18°F (-8°C) | 1.3" | 30.9 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 79°F around July 11, short of 90°F on every date, while 232 dates carry a normal low at or below freezing, the coldest 4°F near January 12.
The freezing stretch
The normal low stays at or below 32°F into May 16, then returns to freezing around September 28, covering 232 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
June 25 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 Green Mt Dam.
Where Green Mt Dam Stands Nationally
Winters bite deep and often: the normal nightly low dips to freezing or below on around 232 nights a year, placing this among the most frost-prone tenth of ranked stations.
Daily temperature swings run wider than most of the country, peaking near 36°F between the normal high and low.
Green Mt Dam earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall
Green Mt Dam 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 21%, with neither reaching the 35% that would mark a distinct wet season. Green Mt Dam has no dry season to plan around, though it does carry a wide 45.9°F gap between its warmest and coldest month.
The gap between the wettest and driest month still matters: April averages 1.9" and November 1.1". The three wettest months together take 32% 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 14
50% probability date
Last Spring Freeze
June 6
50% probability date
Growing Season
100 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
9,619
Higher = more heating needed
Cooling Degree Days
25
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside CO closest to Green Mt Dam 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).
- Bedford, WY 39°F · 0.0°F off
- Bottineau, ND 39°F · 0.0°F off
- Hansboro, ND 39°F · 0.0°F off
- Limestone, ME 39°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (16.5" here), excluding temperature-peer places.
- Prescott, AZ 16.5" · 0.0" off
- Spokane, WA 16.4" · 0.0" off
- Wyola, MT 16.5" · 0.0" off
- Pleasant Grove, UT 16.4" · 0.0" off
Data-derived climate profile
How Green Mt Dam's climate pattern fits together
heating led · dry · mid swing
Green Mt Dam's energy balance leans toward cold weather: 9,619 annual heating degree days against 25 for cooling. Its 45.9°F seasonal range still makes the monthly rows more useful than the annual average alone.
Only about 100 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 Green Mt Dam's middle-range seasonal profile. The measured spread is 45.9°F. The annual average is 39°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Green Mt Dam's cold-season load does not imply a wet climate. Annual precipitation is 16.5 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 Green Mt Dam'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 Green Mt Dam, not an official NOAA class or a year-ahead forecast.
Questions about Green Mt Dam's climate
How much rain does Green Mt Dam get? ▼
How cold does Green Mt Dam get in winter? ▼
How much energy does heating and cooling require in Green Mt Dam? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Green Mt Dam's primary station: GREEN MT DAM (USC00053592). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The conservative exact name-and-state crosswalk finds no Census place match, so PlainClimate treats this as a station-mapped location and does not claim it is a municipality. No exact Gazetteer row for Green Mt Dam; facility counts that depend on place identity are therefore an upper bound, not a municipal census.
On this page every temperature, precipitation, and derived score for Green Mt Dam 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.