Altenbern, Colorado climate: Climate normals at a NOAA weather station
Altenbern's normal year runs from 12°F January nights to 90°F July afternoons, with 17.1 inches of precipitation and 54 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.5°C, January lows of −11°C, July highs of 32°C, 434 mm of precipitation a year.
- NOAA stationAltenbern
- Station IDUSC00050214
- Location39.50°N 108.38°W
- Elevation5,637 ft (1,718 m)
On October 23, the normal high in Altenbern is 62°F and the normal low 29°F, and the chance of measurable rain or snow is 23%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Altenbern.
- Jan 37° 12°
- Feb 44° 18°
- Mar 55° 25°
- Apr 62° 30°
- May 73° 38°
- Jun 84° 44°
- Jul 90° 51°
- Aug 87° 50°
- Sep 78° 42°
- Oct 65° 32°
- Nov 50° 21°
- Dec 37° 13°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Altenbern each month?
July is the warmest month, with normal highs of 90°F; January the coldest, with normal lows of 12°F. The most precipitation falls in September (1.86 in), the least in June (0.79 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 37°F | 12°F | 24.6°F | 1.18 | 11.7 | 8 | <1 | 31 | 9 h 40 min |
| February | 44°F | 18°F | 30.7°F | 1.30 | 10.8 | 9 | <1 | 27 | 10 h 40 min |
| March | 55°F | 25°F | 39.9°F | 1.38 | 5.5 | 8 | <1 | 27 | 11 h 50 min |
| April | 62°F | 30°F | 46.2°F | 1.63 | 2.9 | 9 | <1 | 19 | 13 h 10 min |
| May | 73°F | 38°F | 55.2°F | 1.76 | 0.3 | 9 | 1 | 6 | 14 h 20 min |
| June | 84°F | 44°F | 64.1°F | 0.79 | 0.0 | 5 | 7 | <1 | 15 h |
| July | 90°F | 51°F | 70.4°F | 1.27 | 0.0 | 8 | 18 | <1 | 14 h 40 min |
| August | 87°F | 50°F | 68.2°F | 1.57 | 0.0 | 10 | 10 | <1 | 13 h 50 min |
| September | 78°F | 42°F | 60.0°F | 1.86 | 0.0 | 8 | 2 | 2 | 12 h 30 min |
| October | 65°F | 32°F | 48.1°F | 1.85 | 1.6 | 7 | <1 | 17 | 11 h 10 min |
| November | 50°F | 21°F | 35.6°F | 1.21 | 6.1 | 7 | <1 | 28 | 10 h |
| December | 37°F | 13°F | 24.9°F | 1.27 | 15.2 | 8 | <1 | 31 | 9 h 20 min |
| Year (annual) | 63°F | 31°F | 47.3°F | 17.07 | 54.1 | 96 | 38 | 189 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 3°C | −11°C | −4.1°C | 30 mm | 30 cm |
| February | 6°C | −8°C | −0.7°C | 33 mm | 27 cm |
| March | 13°C | −4°C | 4.4°C | 35 mm | 14 cm |
| April | 17°C | −1°C | 7.9°C | 41 mm | 7 cm |
| May | 23°C | 3°C | 12.9°C | 45 mm | 1 cm |
| June | 29°C | 7°C | 17.8°C | 20 mm | 0 cm |
| July | 32°C | 11°C | 21.3°C | 32 mm | 0 cm |
| August | 30°C | 10°C | 20.1°C | 40 mm | 0 cm |
| September | 26°C | 5°C | 15.6°C | 47 mm | 0 cm |
| October | 18°C | 0°C | 8.9°C | 47 mm | 4 cm |
| November | 10°C | −6°C | 2.0°C | 31 mm | 15 cm |
| December | 3°C | −11°C | −3.9°C | 32 mm | 39 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00050214; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
Which months are mildest at Altenbern?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, June has the fewest days with rain (5).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00050214.
When is the last frost at Altenbern?
In Altenbern, the last spring frost (32°F) comes after May 25 in half of years and after June 13 in one year in ten; the first autumn frost comes before September 25 in half of years and before September 10 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 251 year in 10 after June 13; 9 in 10 after May 10
- First autumn frost, half of years before
- September 251 year in 10 before September 10; 9 in 10 before October 8
NOAA puts the median frost-free season at 120 days, and the season without a hard freeze (28°F) at 148 days.
A hard freeze (28°F) comes after May 8 in half of springs and before October 4 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Altenbern in zone 6b in ZIP code 81630, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 6a: the coldest night of a typical year reaches −10°F (30 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Colorado · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00050214; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get at Altenbern?
In a normal year in Altenbern, 38 days a year reach 90°F (1 of them 100°F or more), 189 nights fall to 32°F or colder and 96 days bring measurable precipitation.
- Days at 90°F or more
- 38a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 189a normal year
- Days that stay below freezing
- 18high of 32°F or less
- Days with 0.01 inch of precipitation
- 96a normal year
- Days with 1 inch of snow or more
- 20a normal year
The highest temperature in this station's record (since 1958) is 104°F, on July 6, 1989; the lowest is −32°F, on January 13, 1963.
The wettest calendar year on that record is 1985, with 24.18 in; the snowiest season is 1992–93, with 119.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00050214; records: ACIS (NOAA Regional Climate Centers), station USC00050214. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Altenbern?
Over a year 81% of the sunlight that would reach the ground under clear skies gets through the clouds at Altenbern, 5.0 kWh per square metre a day. June is the sunniest month (87%) and December the cloudiest (74%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 77% | 2.6 |
| February | 76% | 3.5 |
| March | 77% | 4.8 |
| April | 77% | 6.0 |
| May | 80% | 7.0 |
| June | 87% | 8.0 |
| July | 84% | 7.3 |
| August | 84% | 6.5 |
| September | 86% | 5.5 |
| October | 82% | 4.0 |
| November | 79% | 2.8 |
| December | 74% | 2.2 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How many heating and cooling degree days does Altenbern record?
A normal year at Altenbern brings 6,779 heating degree days, 26% more than the median U.S. place (5,373), and 357 cooling degree days, 61% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,217 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,251 | 0 |
| February | 960 | 0 |
| March | 780 | 0 |
| April | 566 | 0 |
| May | 307 | 3 |
| June | 79 | 52 |
| July | 7 | 173 |
| August | 16 | 115 |
| September | 164 | 14 |
| October | 522 | 0 |
| November | 884 | 0 |
| December | 1,245 | 0 |
| Year (annual) | 6,779 | 357 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00050214. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Have recent years at Altenbern been warmer than normal?
2024 averaged 50.1°F, 2.8°F above the 1991-2020 normal of 47.3°F. 4 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 49.9°F | +2.6°F | 17.11 | 43.2 |
| 2022 | 47.7°F | +0.4°F | 17.08 | 48.6 |
| 2023 | 47.8°F | +0.5°F | 18.06 | 72.3 |
| 2024 | 50.1°F | +2.8°F | 18.89 | 52.3 |
Over 63 complete years from 1959 to 2024, the station's annual mean temperature rose at a fitted 5.3°F per century (+0.29°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00050214; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Altenbern's climate compare?
Altenbern is warmer than 52 of the 125 places with their own NOAA record in Colorado, and wetter than 81. Across the 7,247 U.S. stations with normals, its annual mean of 47.3°F is warmer than 29%.
In the Köppen classification computed from these normals, Altenbern is Dfb: continental, no dry season, warm summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Questions about Altenbern's climate
What is the coldest month at Altenbern?
January, with a normal high of 37°F and a normal low of 12°F. The warmest is July (90°F by day, 51°F at night).
Does it snow at Altenbern?
Yes: 54 inches in a normal year, falling on 28 days with 0.1 inch or more, the most in December (15.2 inches).
What is the rainiest month at Altenbern?
September, with 1.86 in of precipitation in a normal year; the driest is June with 0.79 in.
What plant hardiness zone is Altenbern in?
The USDA's 2023 map puts Altenbern in zone 6b in ZIP code 81630, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −10°F (30 years, 1991-2020): zone 6a.
How late can frost come at Altenbern?
In half of years the last 32°F night comes after May 25; in one year in ten it comes after June 13. Waiting until June 13 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Colorado climateThe statewide normals and every place in the state
- Grand Junction, CO27 miles from this station, 53.2°F a year
- Palisade, CO27 miles from this station, 54.4°F a year
- Collbran, CO28 miles from this station, 47.6°F a year
- Fruita, CO30 miles from this station, 52.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made