Mount Lemmon Willow Canyon, Arizona climate: Climate normals at a NOAA weather station
Mount Lemmon Willow Canyon's normal year runs from 33°F December nights to 80°F July afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.3°C, December lows of 0°C, July highs of 27°C.
- NOAA stationMount Lemmon Willow Canyon
- Station IDUSC00025737
- Location32.39°N 110.70°W
- Elevation7,027 ft (2,142 m)
On October 23, the normal high in Mount Lemmon Willow Canyon is 66°F and the normal low 47°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Mount Lemmon Willow Canyon.
- Jan 50° 34°
- Feb 50° 33°
- Mar 55° 37°
- Apr 62° 43°
- May 71° 51°
- Jun 80° 60°
- Jul 80° 64°
- Aug 79° 62°
- Sep 75° 59°
- Oct 68° 49°
- Nov 59° 40°
- Dec 49° 33°
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 Mount Lemmon Willow Canyon each month?
July is the warmest month, with normal highs of 80°F; December the coldest, with normal lows of 33°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 50°F | 34°F | 41.6°F | – | <1 | 13 | 10 h 10 min |
| February | 50°F | 33°F | 41.6°F | – | <1 | 11 | 11 h |
| March | 55°F | 37°F | 45.7°F | – | <1 | 7 | 12 h |
| April | 62°F | 43°F | 52.4°F | – | <1 | 1 | 13 h |
| May | 71°F | 51°F | 60.6°F | – | <1 | <1 | 13 h 50 min |
| June | 80°F | 60°F | 70.0°F | – | <1 | <1 | 14 h 20 min |
| July | 80°F | 64°F | 71.9°F | – | 3 | <1 | 14 h 10 min |
| August | 79°F | 62°F | 70.7°F | – | 2 | <1 | 13 h 20 min |
| September | 75°F | 59°F | 66.9°F | – | <1 | <1 | 12 h 20 min |
| October | 68°F | 49°F | 58.4°F | – | <1 | 1 | 11 h 30 min |
| November | 59°F | 40°F | 49.7°F | – | <1 | 6 | 10 h 30 min |
| December | 49°F | 33°F | 41.0°F | – | <1 | 14 | 10 h |
| Year (annual) | 65°F | 47°F | 55.9°F | – | 5 | 53 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 10°C | 1°C | 5.3°C |
| February | 10°C | 1°C | 5.3°C |
| March | 13°C | 3°C | 7.6°C |
| April | 17°C | 6°C | 11.3°C |
| May | 21°C | 10°C | 15.9°C |
| June | 27°C | 15°C | 21.1°C |
| July | 27°C | 18°C | 22.2°C |
| August | 26°C | 17°C | 21.5°C |
| September | 24°C | 15°C | 19.4°C |
| October | 20°C | 10°C | 14.7°C |
| November | 15°C | 4°C | 9.8°C |
| December | 10°C | 0°C | 5.0°C |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Oracle (15 miles away), gets 11 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00025737; 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 Mount Lemmon Willow Canyon?
Normal highs sit between 65°F and 85°F in May, June, July, August, September and October.
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 USC00025737.
When is the last frost at Mount Lemmon Willow Canyon?
In Mount Lemmon Willow Canyon, the last spring frost (32°F) comes after April 1 in half of years and after April 21 in one year in ten; the first autumn frost comes before November 19 in half of years and before October 30 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
- April 11 year in 10 after April 21; 9 in 10 after March 13
- First autumn frost, half of years before
- November 191 year in 10 before October 30; 9 in 10 before December 4
NOAA puts the median frost-free season at 229 days, and the season without a hard freeze (28°F) at 261 days.
A hard freeze (28°F) comes after March 12 in half of springs and before November 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Mount Lemmon Willow Canyon in zone 8b in ZIP code 85619, the nearest ZIP area.
Frost dates for every NOAA station in Arizona · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00025737; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 Mount Lemmon Willow Canyon?
In a normal year in Mount Lemmon Willow Canyon, 5 days a year reach 90°F and 53 nights fall to 32°F or colder.
- Days at 90°F or more
- 5a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 53a normal year
- Days that stay below freezing
- 4high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00025737.
How sunny is it at Mount Lemmon Willow Canyon?
Over a year 89% of the sunlight that would reach the ground under clear skies gets through the clouds at Mount Lemmon Willow Canyon, 5.8 kWh per square metre a day. June is the sunniest month (94%) and July the cloudiest (84%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 86% | 3.6 |
| February | 85% | 4.5 |
| March | 89% | 6.0 |
| April | 93% | 7.4 |
| May | 94% | 8.2 |
| June | 94% | 8.3 |
| July | 84% | 6.9 |
| August | 86% | 6.5 |
| September | 88% | 5.9 |
| October | 92% | 5.1 |
| November | 89% | 3.9 |
| December | 85% | 3.3 |
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 many heating and cooling degree days does Mount Lemmon Willow Canyon record?
A normal year at Mount Lemmon Willow Canyon brings 4,024 heating degree days, 25% fewer than the median U.S. place (5,373), and 715 cooling degree days, 21% fewer than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,282 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 727 | 0 |
| February | 655 | 0 |
| March | 600 | 0 |
| April | 379 | 1 |
| May | 170 | 34 |
| June | 12 | 161 |
| July | 5 | 217 |
| August | 3 | 180 |
| September | 37 | 94 |
| October | 232 | 27 |
| November | 461 | 0 |
| December | 743 | 0 |
| Year (annual) | 4,024 | 715 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00025737. 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 Mount Lemmon Willow Canyon been warmer than normal?
2025 averaged 57.7°F, 1.8°F above the 1991-2020 normal of 55.9°F. 3 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal |
|---|---|---|
| 2021 | 56.3°F | +0.4°F |
| 2024 | 56.6°F | +0.7°F |
| 2025 | 57.7°F | +1.8°F |
Source: observed years: ACIS, station USC00025737. A year counts only with all twelve months complete.
How does Mount Lemmon Willow Canyon's climate compare?
Mount Lemmon Willow Canyon is warmer than 18 of the 97 places with their own NOAA record in Arizona. Across the 7,247 U.S. stations with normals, its annual mean of 55.9°F is warmer than 63%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Which places near Mount Lemmon Willow Canyon share this climate record?
2 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.
- Summerhaven, AZ22 people · 6 mi NW
- Willow Canyon, AZ0 people · 0 mi NW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Mount Lemmon Willow Canyon's climate
What is the coldest month at Mount Lemmon Willow Canyon?
December, with a normal high of 49°F and a normal low of 33°F. The warmest is July (80°F by day, 64°F at night).
Does it snow at Mount Lemmon Willow Canyon?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Oracle (15 miles away), records 11 inches of snow in a normal year.
What plant hardiness zone is Mount Lemmon Willow Canyon in?
The USDA's 2023 map puts Mount Lemmon Willow Canyon in zone 8b in ZIP code 85619, the nearest ZIP area.
How late can frost come at Mount Lemmon Willow Canyon?
In half of years the last 32°F night comes after April 1; in one year in ten it comes after April 21. Waiting until April 21 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Arizona climateThe statewide normals and every place in the state
- Catalina, AZ14 miles from this station, 65.6°F a year
- Saguaro National Park, AZ14 miles from this station, 70.0°F a year
- Oracle, AZ15 miles from this station, 62.3°F a year
- San Manuel, AZ16 miles from this station, 66.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made