Cortez, Colorado climate: Normal weather by month, frost dates and records
Cortez's normal year runs from 14°F January nights to 91°F July afternoons, with 11.7 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.4°C, January lows of −10°C, July highs of 33°C, 296 mm of precipitation a year.
- NOAA stationCortez Montezuma County Airport
- Station IDUSW00093069
- Location37.30°N 108.63°W
- Elevation5,914 ft (1,803 m)
- Population9,151
On October 14, the normal high in Cortez is 67°F and the normal low 32°F, and the chance of measurable rain or snow is 18%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Cortez.
- Jan 42° 14°
- Feb 47° 19°
- Mar 57° 24°
- Apr 64° 30°
- May 75° 37°
- Jun 86° 45°
- Jul 91° 54°
- Aug 87° 52°
- Sep 80° 43°
- Oct 67° 31°
- Nov 53° 22°
- Dec 42° 15°
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 Cortez each month?
July is the warmest month, with normal highs of 91°F; January the coldest, with normal lows of 14°F. The most precipitation falls in August (1.59 in), the least in June (0.29 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 42°F | 14°F | 27.7°F | 1.07 | 6 | <1 | 30 | 9 h 50 min |
| February | 47°F | 19°F | 32.8°F | 1.01 | 7 | <1 | 27 | 10 h 50 min |
| March | 57°F | 24°F | 40.4°F | 0.84 | 6 | <1 | 28 | 11 h 50 min |
| April | 64°F | 30°F | 46.9°F | 0.75 | 6 | <1 | 20 | 13 h 10 min |
| May | 75°F | 37°F | 55.9°F | 0.74 | 5 | 1 | 7 | 14 h 10 min |
| June | 86°F | 45°F | 65.5°F | 0.29 | 3 | 12 | 1 | 14 h 40 min |
| July | 91°F | 54°F | 72.2°F | 1.14 | 9 | 21 | <1 | 14 h 30 min |
| August | 87°F | 52°F | 69.9°F | 1.59 | 9 | 12 | <1 | 13 h 40 min |
| September | 80°F | 43°F | 61.4°F | 1.58 | 7 | 2 | 2 | 12 h 30 min |
| October | 67°F | 31°F | 49.0°F | 1.06 | 6 | <1 | 18 | 11 h 20 min |
| November | 53°F | 22°F | 37.5°F | 0.79 | 5 | <1 | 28 | 10 h 10 min |
| December | 42°F | 15°F | 28.6°F | 0.80 | 7 | <1 | 30 | 9 h 40 min |
| Year (annual) | 66°F | 32°F | 49.0°F | 11.66 | 74 | 48 | 191 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 5°C | −10°C | −2.4°C | 27 mm |
| February | 8°C | −7°C | 0.4°C | 26 mm |
| March | 14°C | −4°C | 4.7°C | 21 mm |
| April | 18°C | −1°C | 8.3°C | 19 mm |
| May | 24°C | 3°C | 13.3°C | 19 mm |
| June | 30°C | 7°C | 18.6°C | 7 mm |
| July | 33°C | 12°C | 22.3°C | 29 mm |
| August | 31°C | 11°C | 21.1°C | 40 mm |
| September | 26°C | 6°C | 16.3°C | 40 mm |
| October | 19°C | 0°C | 9.4°C | 27 mm |
| November | 12°C | −6°C | 3.1°C | 20 mm |
| December | 6°C | −9°C | −1.9°C | 20 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Cortez's own co-op station Cortez station does: 33 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USW00093069; 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 Cortez?
Normal highs sit between 65°F and 85°F in May, September and October. Of those, May 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 USW00093069.
When is the last frost in Cortez?
In Cortez, the last spring frost (32°F) comes after May 27 in half of years and after June 11 in one year in ten; the first autumn frost comes before September 28 in half of years and before September 17 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 271 year in 10 after June 11; 9 in 10 after May 9
- First autumn frost, half of years before
- September 281 year in 10 before September 17; 9 in 10 before October 10
NOAA puts the median frost-free season at 125 days, and the season without a hard freeze (28°F) at 150 days.
A hard freeze (28°F) comes after May 8 in half of springs and before October 7 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Cortez in zone 7a in ZIP code 81321, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Cortez's NOAA station is in zone 6a: the coldest night of a typical year reaches −7°F (24 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 USW00093069; 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 Cortez?
In a normal year in Cortez, 48 days a year reach 90°F (1 of them 100°F or more), 191 nights fall to 32°F or colder and 74 days bring measurable precipitation.
- Days at 90°F or more
- 48a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 191a normal year
- Days that stay below freezing
- 10high of 32°F or less
- Days with 0.01 inch of precipitation
- 74a normal year
The highest temperature in this station's record (since 1996) is 103°F, on July 9, 2021; the lowest is −19°F, on January 2, 2011.
The wettest calendar year on that record is 2005, with 15.03 in.
Source: NOAA NCEI 1991-2020 annual normals, station USW00093069; records: ACIS (NOAA Regional Climate Centers), station USW00093069. Records use complete months only; a month missing more than three days is left out.
How sunny is Cortez?
Over a year 83% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Cortez, 5.3 kWh per square metre a day. June is the sunniest month (91%) and December the cloudiest (75%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 78% | 2.8 |
| February | 76% | 3.7 |
| March | 80% | 5.1 |
| April | 81% | 6.4 |
| May | 84% | 7.5 |
| June | 91% | 8.3 |
| July | 85% | 7.3 |
| August | 84% | 6.5 |
| September | 86% | 5.7 |
| October | 85% | 4.4 |
| November | 83% | 3.2 |
| December | 75% | 2.4 |
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 Cortez need?
A normal year in Cortez brings 6,304 heating degree days, 17% more than the median U.S. place (5,373), and 488 cooling degree days, 46% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,432 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,156 | 0 |
| February | 900 | 0 |
| March | 763 | 0 |
| April | 542 | 0 |
| May | 289 | 7 |
| June | 61 | 74 |
| July | 2 | 225 |
| August | 8 | 158 |
| September | 134 | 25 |
| October | 496 | 0 |
| November | 825 | 0 |
| December | 1,130 | 0 |
| Year (annual) | 6,304 | 488 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00093069. 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 Cortez been warmer than normal lately?
2025 averaged 50.9°F, 1.9°F above the 1991-2020 normal of 49.0°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 50.3°F | +1.3°F | 11.82 |
| 2022 | 49.9°F | +0.9°F | 10.02 |
| 2023 | 48.9°F | −0.1°F | 11.83 |
| 2024 | 50.8°F | +1.8°F | 13.04 |
| 2025 | 50.9°F | +1.9°F | 9.38 |
Source: observed years: ACIS, station USW00093069. A year counts only with all twelve months complete.
How does Cortez's climate compare?
Cortez is warmer than 64 of the other 124 places with their own NOAA record in Colorado, and wetter than 21. Across the 7,247 U.S. stations with normals, its annual mean of 49.0°F is warmer than 36%.
In the Köppen classification computed from these normals, Cortez is BSk: cold semi-arid steppe. 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 Cortez share this climate record?
Towaoc has no NOAA station with 1991-2020 normals of its 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.
- Towaoc, CO1,058 people · 8 mi SW
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 Cortez's other NOAA stations record?
2 more NOAA stations keep 1991-2020 normals in or near Cortez. This page uses Cortez Montezuma County Airport; the others differ by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Cortez (8 mi SE) USW00003061 | 8 mi SE | 8,034 ft | 47.9°F | 22°F | 82°F | 18.6 | – | May 6 |
| Cortez station USC00051886 | 3 mi NE | 6,167 ft | 50.8°F | 17°F | 91°F | 11.8 | 33 | May 12 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Cortez's climate
What is the coldest month in Cortez?
January, with a normal high of 42°F and a normal low of 14°F. The warmest is July (91°F by day, 54°F at night).
Does it snow in Cortez?
Yes. NOAA publishes no 1991-2020 snowfall normal for Cortez's NOAA station; Cortez's own co-op station Cortez station records 33 inches of snow in a normal year.
What is the rainiest month in Cortez?
August, with 1.59 in of precipitation in a normal year; the driest is June with 0.29 in.
What plant hardiness zone is Cortez in?
The USDA's 2023 map puts Cortez in zone 7a in ZIP code 81321, the nearest ZIP area. By the same method at Cortez's NOAA station, the coldest night of a typical year reaches −7°F (24 years, 1991-2020): zone 6a.
How late can frost come in Cortez?
In half of years the last 32°F night comes after May 27; in one year in ten it comes after June 11. Waiting until June 11 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Colorado climateThe statewide normals and every place in the state
- Mesa Verde National Park, CO11 miles from this station, 49.9°F a year
- Yellow Jacket (2 mi W), CO17 miles from this station, 49.5°F a year
- Mancos, CO17 miles from this station, 46.3°F a year
- Yellow Jacket (4 mi NE), CO18 miles from this station, 48.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made