Superior, Arizona climate: Normal weather by month, frost dates and records
Superior's normal year runs from 44°F December nights to 99°F July afternoons, with 17.8 inches of precipitation and less than an inch of snow (0.3 in) a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 21.2°C, December lows of 7°C, July highs of 37°C, 452 mm of precipitation a year.
- NOAA stationSuperior
- Station IDUSC00028348
- Location33.30°N 111.10°W
- Elevation2,860 ft (872 m)
- From the center3 miles
- Population2,682
On October 23, the normal high in Superior is 82°F and the normal low 61°F, and the chance of measurable rain or snow is 11%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Superior.
- Jan 62° 44°
- Feb 65° 46°
- Mar 72° 49°
- Apr 78° 55°
- May 87° 64°
- Jun 97° 73°
- Jul 99° 77°
- Aug 97° 77°
- Sep 93° 72°
- Oct 84° 63°
- Nov 73° 52°
- Dec 62° 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 in Superior each month?
July is the warmest month, with normal highs of 99°F; December the coldest, with normal lows of 44°F. The most precipitation falls in August (2.56 in), the least in June (0.29 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 62°F | 44°F | 53.1°F | 2.23 | 5 | <1 | 1 | 10 h 10 min |
| February | 65°F | 46°F | 55.5°F | 2.21 | 6 | <1 | <1 | 11 h |
| March | 72°F | 49°F | 60.4°F | 1.87 | 6 | <1 | <1 | 12 h |
| April | 78°F | 55°F | 66.6°F | 0.49 | 2 | 2 | <1 | 13 h |
| May | 87°F | 64°F | 75.4°F | 0.49 | 2 | 13 | <1 | 13 h 50 min |
| June | 97°F | 73°F | 85.1°F | 0.29 | 1 | 26 | <1 | 14 h 20 min |
| July | 99°F | 77°F | 88.0°F | 2.03 | 5 | 29 | <1 | 14 h 10 min |
| August | 97°F | 77°F | 86.8°F | 2.56 | 8 | 28 | <1 | 13 h 30 min |
| September | 93°F | 72°F | 82.7°F | 1.25 | 3 | 23 | <1 | 12 h 30 min |
| October | 84°F | 63°F | 73.5°F | 1.14 | 3 | 8 | <1 | 11 h 20 min |
| November | 73°F | 52°F | 62.3°F | 1.12 | 3 | <1 | <1 | 10 h 30 min |
| December | 62°F | 44°F | 53.0°F | 2.12 | 4 | <1 | 1 | 10 h |
| Year (annual) | 81°F | 60°F | 70.2°F | 17.80 | 49 | 129 | 3 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 17°C | 7°C | 11.7°C | 57 mm |
| February | 18°C | 8°C | 13.1°C | 56 mm |
| March | 22°C | 10°C | 15.8°C | 47 mm |
| April | 26°C | 13°C | 19.2°C | 12 mm |
| May | 30°C | 18°C | 24.1°C | 12 mm |
| June | 36°C | 23°C | 29.5°C | 7 mm |
| July | 37°C | 25°C | 31.1°C | 52 mm |
| August | 36°C | 25°C | 30.4°C | 65 mm |
| September | 34°C | 22°C | 28.2°C | 32 mm |
| October | 29°C | 17°C | 23.1°C | 29 mm |
| November | 23°C | 11°C | 16.8°C | 28 mm |
| December | 17°C | 7°C | 11.7°C | 54 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00028348; 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 Superior?
Normal highs sit between 65°F and 85°F in March, April, October and November. Of those, April 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 USC00028348.
When is the last frost in Superior?
In Superior, the last spring frost (32°F) comes after January 18 in half of years and after March 1 in one year in ten; the first autumn frost comes before December 28 in half of years and before December 1 in one year in ten. A night at 32°F or colder comes at all in 77% 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 181 year in 10 after March 1; 9 in 10 after December 19
- First autumn frost, half of years before
- December 281 year in 10 before December 1; 9 in 10 before February 1
NOAA puts the median frost-free season at 342 days, and the season without a hard freeze (28°F) at 365 days.
A hard freeze (28°F) comes after January 9 in half of springs and before January 7 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Superior in zone 9b in ZIP code 85173, 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 USC00028348; 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 in Superior?
In a normal year in Superior, 129 days a year reach 90°F (36 of them 100°F or more), 3 nights fall to 32°F or colder and 49 days bring measurable precipitation.
- Days at 90°F or more
- 129a normal year
- Days at 100°F or more
- 36a 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
- 49a normal year
The highest temperature in this station's record (since 1953) is 112°F, on July 29, 1995; the lowest is 19°F, on December 8, 1978.
The wettest calendar year on that record is 1992, with 36.23 in; the snowiest season is 1968–69, with 9.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00028348; records: ACIS (NOAA Regional Climate Centers), station USC00028348. Records use complete months only; a month missing more than three days is left out.
How sunny is Superior?
Over a year 91% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Superior, 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 much heating and cooling does Superior need?
A normal year in Superior brings 1,454 heating degree days, 73% fewer than the median U.S. place (5,373), and 3,383 cooling degree days, 3.7 times the median (908). Two months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 7,546 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 369 | 2 |
| February | 270 | 5 |
| March | 186 | 43 |
| April | 72 | 118 |
| May | 11 | 332 |
| June | 1 | 603 |
| July | 0 | 714 |
| August | 0 | 676 |
| September | 0 | 533 |
| October | 22 | 287 |
| November | 150 | 67 |
| December | 375 | 3 |
| Year (annual) | 1,454 | 3,383 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00028348. 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 Superior's climate compare?
Superior is warmer than 65 of the other 96 places with their own NOAA record in Arizona, and wetter than 76. Across the 7,247 U.S. stations with normals, its annual mean of 70.2°F is warmer than 95%.
In the Köppen classification computed from these normals, Superior 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.
Which places near Superior share this climate record?
3 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.
- Kearny, AZ1,898 people · 20 mi SE
- Queen Valley, AZ799 people · 12 mi W
- Top-of-the-World, AZ125 people · 7 mi NE
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 Superior's climate
What is the coldest month in Superior?
December, with a normal high of 62°F and a normal low of 44°F. The warmest is July (99°F by day, 77°F at night).
Does it snow in Superior?
Rarely: NOAA's normal is 0.3 inch a year.
What is the rainiest month in Superior?
August, with 2.56 in of precipitation in a normal year; the driest is June with 0.29 in.
What plant hardiness zone is Superior in?
The USDA's 2023 map puts Superior in zone 9b in ZIP code 85173, the nearest ZIP area.
How late can frost come in Superior?
In half of years the last 32°F night comes after January 18; in one year in ten it comes after March 1. Waiting until March 1 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Arizona climateThe statewide normals and every place in the state
- Miami, AZ15 miles from this station, 66.8°F a year
- Globe, AZ19 miles from this station, 63.6°F a year
- Roosevelt, AZ24 miles from this station, 70.2°F a year
- Florence, AZ25 miles from this station, 72.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made