Aspen, Colorado climate: Normal weather by month, frost dates and records
Aspen's normal year runs from 9°F January nights to 82°F July afternoons, with 14.9 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 6.0°C, January lows of −13°C, July highs of 28°C, 379 mm of precipitation a year.
- NOAA stationAspen Pitkin County Airport
- Station IDUSW00093073
- Location39.22°N 106.87°W
- Elevation7,720 ft (2,353 m)
- Population6,556
On October 10, the normal high in Aspen is 62°F and the normal low 31°F, and the chance of measurable rain or snow is 27%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Aspen.
- Jan 35° 9°
- Feb 38° 12°
- Mar 46° 21°
- Apr 55° 28°
- May 65° 35°
- Jun 77° 42°
- Jul 82° 48°
- Aug 80° 47°
- Sep 72° 40°
- Oct 60° 29°
- Nov 45° 19°
- Dec 34° 9°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Aspen each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 9°F. The most precipitation falls in April (1.80 in), the least in December (0.82 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 35°F | 9°F | 21.7°F | 1.05 | 11 | <1 | 31 | 9 h 40 min |
| February | 38°F | 12°F | 25.2°F | 0.90 | 11 | <1 | 28 | 10 h 40 min |
| March | 46°F | 21°F | 33.5°F | 1.03 | 10 | <1 | 30 | 11 h 50 min |
| April | 55°F | 28°F | 41.3°F | 1.80 | 12 | <1 | 25 | 13 h 10 min |
| May | 65°F | 35°F | 50.0°F | 1.52 | 10 | <1 | 12 | 14 h 20 min |
| June | 77°F | 42°F | 59.6°F | 0.88 | 6 | <1 | 1 | 14 h 50 min |
| July | 82°F | 48°F | 65.2°F | 1.64 | 12 | 1 | <1 | 14 h 40 min |
| August | 80°F | 47°F | 63.3°F | 1.48 | 12 | <1 | <1 | 13 h 50 min |
| September | 72°F | 40°F | 56.1°F | 1.43 | 9 | <1 | 4 | 12 h 30 min |
| October | 60°F | 29°F | 44.4°F | 1.33 | 9 | <1 | 22 | 11 h 10 min |
| November | 45°F | 19°F | 32.0°F | 1.04 | 9 | <1 | 29 | 10 h |
| December | 34°F | 9°F | 21.8°F | 0.82 | 11 | <1 | 31 | 9 h 30 min |
| Year (annual) | 57°F | 28°F | 42.8°F | 14.92 | 120 | 2 | 212 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 1°C | −13°C | −5.7°C | 27 mm |
| February | 3°C | −11°C | −3.8°C | 23 mm |
| March | 8°C | −6°C | 0.8°C | 26 mm |
| April | 13°C | −2°C | 5.2°C | 46 mm |
| May | 18°C | 2°C | 10.0°C | 39 mm |
| June | 25°C | 6°C | 15.3°C | 22 mm |
| July | 28°C | 9°C | 18.4°C | 42 mm |
| August | 26°C | 8°C | 17.4°C | 38 mm |
| September | 22°C | 4°C | 13.4°C | 36 mm |
| October | 15°C | −2°C | 6.9°C | 34 mm |
| November | 7°C | −7°C | 0.0°C | 26 mm |
| December | 1°C | −13°C | −5.7°C | 21 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Aspen's own co-op station Aspen (1 mi SW) does: 171 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USW00093073; 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.
When is the best weather to visit Aspen?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, June has the fewest days with rain (6).
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 USW00093073.
When is the last frost in Aspen?
In Aspen, the last spring frost (32°F) comes after May 31 in half of years and after June 14 in one year in ten; the first autumn frost comes before September 23 in half of years and before September 11 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 311 year in 10 after June 14; 9 in 10 after May 16
- First autumn frost, half of years before
- September 231 year in 10 before September 11; 9 in 10 before October 3
NOAA puts the median frost-free season at 114 days, and the season without a hard freeze (28°F) at 140 days.
A hard freeze (28°F) comes after May 13 in half of springs and before October 2 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Aspen in zone 5b in ZIP code 81615, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Aspen's NOAA station is in zone 5b: the coldest night of a typical year reaches −14°F (22 complete years).
Frost dates for every NOAA station in Colorado · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00093073; 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 in Aspen?
In a normal year in Aspen, 2 days a year reach 90°F, 212 nights fall to 32°F or colder and 120 days bring measurable precipitation.
- Days at 90°F or more
- 2a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 212a normal year
- Days that stay below freezing
- 46high of 32°F or less
- Days with 0.01 inch of precipitation
- 120a normal year
The highest temperature in this station's record (since 1998) is 93°F, on July 21, 2026; the lowest is −26°F, on February 3, 2011.
The wettest calendar year on that record is 2015, with 18.52 in.
Source: NOAA NCEI 1991-2020 annual normals, station USW00093073; records: ACIS (NOAA Regional Climate Centers), station USW00093073. Records use complete months only; a month missing more than three days is left out.
How sunny is Aspen?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Aspen, 4.8 kWh per square metre a day. March is the sunniest month (81%) and May the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 79% | 2.7 |
| February | 78% | 3.7 |
| March | 81% | 5.2 |
| April | 74% | 5.8 |
| May | 70% | 6.3 |
| June | 81% | 7.5 |
| July | 77% | 6.7 |
| August | 76% | 5.9 |
| September | 80% | 5.2 |
| October | 76% | 3.8 |
| November | 75% | 2.8 |
| December | 74% | 2.3 |
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 much heating and cooling does Aspen need?
A normal year in Aspen brings 8,142 heating degree days, 52% more than the median U.S. place (5,373), and 90 cooling degree days, 90% 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 1,507 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,344 | 0 |
| February | 1,114 | 0 |
| March | 977 | 0 |
| April | 710 | 0 |
| May | 464 | 0 |
| June | 175 | 13 |
| July | 40 | 47 |
| August | 77 | 26 |
| September | 269 | 2 |
| October | 640 | 0 |
| November | 992 | 0 |
| December | 1,341 | 0 |
| Year (annual) | 8,142 | 90 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00093073. 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.
Has Aspen been warmer than normal lately?
2025 averaged 44.1°F, 1.3°F above the 1991-2020 normal of 42.8°F. 3 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 44.2°F | +1.4°F | 14.70 |
| 2022 | 41.8°F | −1.0°F | 14.77 |
| 2023 | 41.4°F | −1.4°F | 12.86 |
| 2024 | 42.9°F | +0.1°F | 15.96 |
| 2025 | 44.1°F | +1.3°F | 9.52 |
Source: observed years: ACIS, station USW00093073. A year counts only with all twelve months complete.
How does Aspen's climate compare?
Aspen is warmer than 26 of the other 124 places with their own NOAA record in Colorado, and wetter than 49. Across the 7,247 U.S. stations with normals, its annual mean of 42.8°F is warmer than 12%.
In the Köppen classification computed from these normals, Aspen 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.
Which places near Aspen share this climate record?
4 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Basalt, CO4,001 people · 14 mi NW
- Snowmass Village, CO2,925 people · 4 mi W
- Redstone, CO157 people · 20 mi W
- Woody Creek, CO123 people · 3 mi N
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Aspen's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Aspen. This page uses Aspen Pitkin County Airport; the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Aspen (1 mi SW) USC00050372 | 3 mi SE | 8,175 ft | 40.6°F | 10°F | 76°F | 24.4 | 171 | June 2 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Aspen's climate
What is the coldest month in Aspen?
January, with a normal high of 35°F and a normal low of 9°F. The warmest is July (82°F by day, 48°F at night).
Does it snow in Aspen?
Yes. NOAA publishes no 1991-2020 snowfall normal for Aspen's NOAA station; Aspen's own co-op station Aspen (1 mi SW) records 171 inches of snow in a normal year.
What is the rainiest month in Aspen?
April, with 1.80 in of precipitation in a normal year; the driest is December with 0.82 in.
What plant hardiness zone is Aspen in?
The USDA's 2023 map puts Aspen in zone 5b in ZIP code 81615, the nearest ZIP area. By the same method at Aspen's NOAA station, the coldest night of a typical year reaches −14°F (22 years, 1991-2020): zone 5b.
How late can frost come in Aspen?
In half of years the last 32°F night comes after May 31; in one year in ten it comes after June 14. Waiting until June 14 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Aspen in OctoberThis month day by day, its records and recent years
- Colorado climateThe statewide normals and every place in the state
- Meredith, CO12 miles from this station, 38.7°F a year
- Crested Butte, CO25 miles from this station, 34.2°F a year
- Sugarloaf Reservoir, CO27 miles from this station, 35.2°F a year
- Twin Lakes, CO29 miles from this station, 37.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made