Window Rock, Arizona climate: Normal weather by month, frost dates and records
Window Rock's normal year runs from 14°F December nights to 88°F July afternoons, with 11.3 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.6°C, December lows of −10°C, July highs of 31°C, 288 mm of precipitation a year.
- NOAA stationWindow Rock Airport
- Station IDUSW00003029
- Location35.66°N 109.06°W
- Elevation6,739 ft (2,054 m)
- Population (census place)2,384
On October 23, the normal high in Window Rock is 65°F and the normal low 28°F, and the chance of measurable rain or snow is 20%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Window Rock.
- Jan 45° 14°
- Feb 49° 19°
- Mar 58° 24°
- Apr 65° 29°
- May 74° 36°
- Jun 85° 45°
- Jul 88° 55°
- Aug 85° 52°
- Sep 79° 43°
- Oct 68° 31°
- Nov 56° 21°
- Dec 46° 14°
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 Window Rock each month?
July is the warmest month, with normal highs of 88°F; December the coldest, with normal lows of 14°F. The most precipitation falls in August (1.85 in), the least in June (0.28 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 45°F | 14°F | 29.9°F | 1.04 | 6 | <1 | 30 | 10 h |
| February | 49°F | 19°F | 34.2°F | 0.87 | 6 | <1 | 27 | 10 h 50 min |
| March | 58°F | 24°F | 40.7°F | 0.66 | 5 | <1 | 29 | 11 h 50 min |
| April | 65°F | 29°F | 46.8°F | 0.46 | 5 | <1 | 21 | 13 h |
| May | 74°F | 36°F | 55.1°F | 0.57 | 4 | <1 | 9 | 14 h |
| June | 85°F | 45°F | 65.2°F | 0.28 | 3 | 7 | 1 | 14 h 30 min |
| July | 88°F | 55°F | 71.5°F | 1.78 | 11 | 11 | <1 | 14 h 20 min |
| August | 85°F | 52°F | 68.5°F | 1.85 | 11 | 4 | <1 | 13 h 30 min |
| September | 79°F | 43°F | 60.8°F | 1.34 | 7 | 1 | 3 | 12 h 30 min |
| October | 68°F | 31°F | 49.2°F | 0.92 | 6 | <1 | 19 | 11 h 20 min |
| November | 56°F | 21°F | 38.6°F | 0.75 | 5 | <1 | 27 | 10 h 20 min |
| December | 46°F | 14°F | 29.7°F | 0.83 | 7 | <1 | 30 | 9 h 50 min |
| Year (annual) | 67°F | 32°F | 49.2°F | 11.35 | 76 | 24 | 196 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 7°C | −10°C | −1.2°C | 26 mm |
| February | 10°C | −7°C | 1.2°C | 22 mm |
| March | 14°C | −5°C | 4.8°C | 17 mm |
| April | 18°C | −2°C | 8.2°C | 12 mm |
| May | 23°C | 2°C | 12.8°C | 14 mm |
| June | 30°C | 7°C | 18.4°C | 7 mm |
| July | 31°C | 13°C | 21.9°C | 45 mm |
| August | 29°C | 11°C | 20.3°C | 47 mm |
| September | 26°C | 6°C | 16.0°C | 34 mm |
| October | 20°C | −1°C | 9.6°C | 23 mm |
| November | 13°C | −6°C | 3.7°C | 19 mm |
| December | 8°C | −10°C | −1.3°C | 21 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Gallup (18 miles away), gets 34 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00003029; 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 Window Rock?
Normal highs sit between 65°F and 85°F in May, August, September and October. Of those, May has the fewest days with rain (4).
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 USW00003029.
When is the last frost in Window Rock?
In Window Rock, the last spring frost (32°F) comes after May 29 in half of years and after June 10 in one year in ten; the first autumn frost comes before September 28 in half of years and before September 16 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 291 year in 10 after June 10; 9 in 10 after May 12
- First autumn frost, half of years before
- September 281 year in 10 before September 16; 9 in 10 before October 8
NOAA puts the median frost-free season at 121 days, and the season without a hard freeze (28°F) at 143 days.
A hard freeze (28°F) comes after May 13 in half of springs and before October 4 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Window Rock in zone 6b in ZIP code 86515, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Window Rock's NOAA station is in zone 6a: the coldest night of a typical year reaches −10°F (18 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 Arizona · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00003029; 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 Window Rock?
In a normal year in Window Rock, 24 days a year reach 90°F, 196 nights fall to 32°F or colder and 76 days bring measurable precipitation.
- Days at 90°F or more
- 24a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 196a normal year
- Days that stay below freezing
- 8high of 32°F or less
- Days with 0.01 inch of precipitation
- 76a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USW00003029.
How sunny is Window Rock?
Over a year 86% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Window Rock, 5.6 kWh per square metre a day. June is the sunniest month (92%) and December the cloudiest (79%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 81% | 3.1 |
| February | 81% | 4.1 |
| March | 85% | 5.6 |
| April | 87% | 7.0 |
| May | 89% | 7.9 |
| June | 92% | 8.4 |
| July | 84% | 7.2 |
| August | 85% | 6.6 |
| September | 88% | 5.9 |
| October | 89% | 4.8 |
| November | 87% | 3.6 |
| December | 79% | 2.8 |
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 Window Rock need?
A normal year in Window Rock brings 6,158 heating degree days, 15% more than the median U.S. place (5,373), and 414 cooling degree days, 54% 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 2,321 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,090 | 0 |
| February | 862 | 0 |
| March | 755 | 0 |
| April | 546 | 0 |
| May | 309 | 4 |
| June | 63 | 69 |
| July | 1 | 204 |
| August | 11 | 120 |
| September | 142 | 16 |
| October | 490 | 0 |
| November | 794 | 0 |
| December | 1,094 | 0 |
| Year (annual) | 6,158 | 414 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00003029. 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 Window Rock been warmer than normal lately?
2025 averaged 49.5°F, 0.3°F above the 1991-2020 normal of 49.2°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 50.5°F | +1.3°F | 9.80 |
| 2022 | 50.1°F | +0.9°F | 16.37 |
| 2023 | 47.7°F | −1.5°F | 10.89 |
| 2024 | 49.3°F | +0.1°F | 12.60 |
| 2025 | 49.5°F | +0.3°F | 7.21 |
Source: observed years: ACIS, station USW00003029. A year counts only with all twelve months complete.
How does Window Rock's climate compare?
Window Rock is warmer than 7 of the other 96 places with their own NOAA record in Arizona, and wetter than 46. Across the 7,247 U.S. stations with normals, its annual mean of 49.2°F is warmer than 37%.
In the Köppen classification computed from these normals, Window Rock 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 Window Rock share this climate record?
16 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.
- Fort Defiance, AZ3,614 people · 6 mi N
- Navajo, NM2,133 people · 17 mi N
- Rock Springs, NM1,166 people · 13 mi E
- Twin Lakes, NM961 people · 16 mi E
- St. Michaels, AZ888 people · 2 mi W
- Tohatchi, NM695 people · 22 mi NE
- Sawmill, AZ666 people · 17 mi N
- Brimhall Nizhoni, NM497 people · 26 mi E
- Yah-ta-hey, NM480 people · 15 mi E
- Naschitti, NM401 people · 35 mi NE
- Crystal, NM302 people · 26 mi N
- Nakaibito, NM251 people · 17 mi NE
- Tse Bonito, NM86 people · 3 mi E
- Purty Rock, NM85 people · 15 mi SE
- Manuelito, NM37 people · 16 mi S
- Black Hat, NM1 people · 6 mi E
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 Window Rock's climate
What is the coldest month in Window Rock?
December, with a normal high of 46°F and a normal low of 14°F. The warmest is July (88°F by day, 55°F at night).
Does it snow in Window Rock?
Yes. NOAA publishes no 1991-2020 snowfall normal for Window Rock's NOAA station; the nearest record that keeps one, Gallup (18 miles away), records 34 inches of snow in a normal year.
What is the rainiest month in Window Rock?
August, with 1.85 in of precipitation in a normal year; the driest is June with 0.28 in.
What plant hardiness zone is Window Rock in?
The USDA's 2023 map puts Window Rock in zone 6b in ZIP code 86515, the nearest ZIP area. By the same method at Window Rock's NOAA station, the coldest night of a typical year reaches −10°F (18 years, 1991-2020): zone 6a.
How late can frost come in Window Rock?
In half of years the last 32°F night comes after May 29; in one year in ten it comes after June 10. Waiting until June 10 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Arizona climateThe statewide normals and every place in the state
- Gallup, NM18 miles from this station, 49.5°F a year
- Ganado, AZ28 miles from this station, 50.9°F a year
- Sanders, AZ34 miles from this station, 52.2°F a year
- McGaffey, NM41 miles from this station, 46.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made