Mormon Flat, Arizona climate: Climate normals at a NOAA weather station
Mormon Flat's normal year runs from 44°F December nights to 106°F July afternoons, with 12.0 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 22.9°C, December lows of 7°C, July highs of 41°C, 305 mm of precipitation a year.
- NOAA stationMormon Flat
- Station IDUSC00025700
- Location33.55°N 111.44°W
- Elevation1,705 ft (520 m)
On October 23, the normal high in Mormon Flat is 86°F and the normal low 60°F, and the chance of measurable rain or snow is 7%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Mormon Flat.
- Jan 68° 44°
- Feb 70° 45°
- Mar 77° 50°
- Apr 85° 55°
- May 94° 64°
- Jun 104° 73°
- Jul 106° 80°
- Aug 104° 79°
- Sep 98° 74°
- Oct 89° 63°
- Nov 75° 52°
- Dec 65° 44°
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 Mormon Flat each month?
July is the warmest month, with normal highs of 106°F; December the coldest, with normal lows of 44°F. The most precipitation falls in January (1.92 in), the least in June (0.04 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 68°F | 44°F | 55.8°F | 1.92 | 5 | <1 | 1 | 10 h 10 min |
| February | 70°F | 45°F | 57.5°F | 1.48 | 5 | <1 | 1 | 11 h |
| March | 77°F | 50°F | 63.8°F | 1.72 | 5 | 1 | <1 | 12 h |
| April | 85°F | 55°F | 70.4°F | 0.47 | 2 | 9 | <1 | 13 h |
| May | 94°F | 64°F | 78.9°F | 0.28 | 2 | 23 | <1 | 13 h 50 min |
| June | 104°F | 73°F | 88.3°F | 0.04 | 1 | 30 | <1 | 14 h 20 min |
| July | 106°F | 80°F | 92.8°F | 1.32 | 4 | 31 | <1 | 14 h 10 min |
| August | 104°F | 79°F | 91.4°F | 1.41 | 5 | 30 | <1 | 13 h 30 min |
| September | 98°F | 74°F | 86.3°F | 0.48 | 3 | 28 | <1 | 12 h 30 min |
| October | 89°F | 63°F | 75.7°F | 0.74 | 3 | 17 | <1 | 11 h 20 min |
| November | 75°F | 52°F | 63.2°F | 0.42 | 2 | 2 | <1 | 10 h 30 min |
| December | 65°F | 44°F | 54.6°F | 1.72 | 4 | <1 | 1 | 10 h |
| Year (annual) | 86°F | 60°F | 73.2°F | 12.00 | 38 | 170 | 3 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 20°C | 7°C | 13.2°C | 49 mm |
| February | 21°C | 7°C | 14.2°C | 38 mm |
| March | 25°C | 10°C | 17.7°C | 44 mm |
| April | 30°C | 13°C | 21.3°C | 12 mm |
| May | 34°C | 18°C | 26.1°C | 7 mm |
| June | 40°C | 23°C | 31.3°C | 1 mm |
| July | 41°C | 27°C | 33.8°C | 34 mm |
| August | 40°C | 26°C | 33.0°C | 36 mm |
| September | 37°C | 23°C | 30.2°C | 12 mm |
| October | 32°C | 17°C | 24.3°C | 19 mm |
| November | 24°C | 11°C | 17.3°C | 11 mm |
| December | 18°C | 7°C | 12.6°C | 44 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00025700; 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 Mormon Flat?
Normal highs sit between 65°F and 85°F in January, February, March, November and December. Of those, November has the fewest days with rain (2).
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 USC00025700.
When is the last frost at Mormon Flat?
In Mormon Flat, the last spring frost (32°F) comes after January 29 in half of years and after February 23 in one year in ten; the first autumn frost comes before December 24 in half of years and before December 3 in one year in ten. A night at 32°F or colder comes at all in 87% of years here (NOAA).
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- January 291 year in 10 after February 23; 9 in 10 after December 23
- First autumn frost, half of years before
- December 241 year in 10 before December 3; 9 in 10 before January 28
NOAA puts the median frost-free season at 334 days, and the season without a hard freeze (28°F) at 365 days.
A hard freeze (28°F) comes after January 10 in half of springs and before January 2 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Mormon Flat in zone 9b in ZIP code 85264, 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 USC00025700; 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 Mormon Flat?
In a normal year in Mormon Flat, 170 days a year reach 90°F (98 of them 100°F or more), 3 nights fall to 32°F or colder and 38 days bring measurable precipitation.
- Days at 90°F or more
- 170a normal year
- Days at 100°F or more
- 98a normal year
- Nights at 32°F or colder
- 3a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 38a normal year
The highest temperature in this station's record (since 1923) is 120°F, on June 26, 1970; the lowest is 20°F, on January 22, 1937.
The wettest calendar year on that record is 1978, with 28.02 in; the snowiest season is 1948–49, with 1.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00025700; records: ACIS (NOAA Regional Climate Centers), station USC00025700. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Mormon Flat?
Over a year 91% of the sunlight that would reach the ground under clear skies gets through the clouds at Mormon Flat, 5.8 kWh per square metre a day. June is the sunniest month (97%) and December the cloudiest (84%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 85% | 3.4 |
| February | 84% | 4.3 |
| March | 89% | 5.8 |
| April | 93% | 7.3 |
| May | 95% | 8.2 |
| June | 97% | 8.5 |
| July | 91% | 7.4 |
| August | 91% | 6.8 |
| September | 93% | 6.1 |
| October | 93% | 5.0 |
| November | 89% | 3.8 |
| December | 84% | 3.0 |
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 Mormon Flat record?
A normal year at Mormon Flat brings 1,104 heating degree days, 79% fewer than the median U.S. place (5,373), and 4,126 cooling degree days, 4.5 times the median (908). One month needs 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 8,553 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 290 | 3 |
| February | 216 | 5 |
| March | 106 | 68 |
| April | 22 | 184 |
| May | 3 | 434 |
| June | 0 | 699 |
| July | 0 | 862 |
| August | 0 | 817 |
| September | 0 | 637 |
| October | 11 | 341 |
| November | 131 | 76 |
| December | 325 | 2 |
| Year (annual) | 1,104 | 4,126 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00025700. 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.
How does Mormon Flat's climate compare?
Mormon Flat is warmer than 85 of the 97 places with their own NOAA record in Arizona, and wetter than 50. Across the 7,247 U.S. stations with normals, its annual mean of 73.2°F is warmer than 98%.
In the Köppen classification computed from these normals, Mormon Flat is BSh: hot 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.
Questions about Mormon Flat's climate
What is the coldest month at Mormon Flat?
December, with a normal high of 65°F and a normal low of 44°F. The warmest is July (106°F by day, 80°F at night).
Does it snow at Mormon Flat?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month at Mormon Flat?
January, with 1.92 in of precipitation in a normal year; the driest is June with 0.04 in.
What plant hardiness zone is Mormon Flat in?
The USDA's 2023 map puts Mormon Flat in zone 9b in ZIP code 85264, the nearest ZIP area.
How late can frost come at Mormon Flat?
In half of years the last 32°F night comes after January 29; in one year in ten it comes after February 23. Waiting until February 23 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Arizona climateThe statewide normals and every place in the state
- Stewart Mountain Dam, AZ6 miles from this station, 71.1°F a year
- Apache Junction, AZ7 miles from this station, 71.9°F a year
- Mesa, AZ15 miles from this station, 72.2°F a year
- Fountain Hills, AZ16 miles from this station, 72.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made