San Carlos, Arizona climate: Normal weather by month, frost dates and records
San Carlos's normal year runs from 31°F December nights to 99°F July afternoons, with 13.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 18.2°C, December lows of 0°C, July highs of 37°C, 341 mm of precipitation a year.
- NOAA stationSan Carlos Reservoir
- Station IDUSC00027480
- Location33.18°N 110.53°W
- Elevation2,532 ft (772 m)
- Population (census place)4,769
On October 14, the normal high in San Carlos is 83°F and the normal low 52°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 San Carlos.
- Jan 59° 31°
- Feb 63° 35°
- Mar 70° 39°
- Apr 78° 47°
- May 88° 56°
- Jun 98° 65°
- Jul 99° 71°
- Aug 97° 70°
- Sep 93° 63°
- Oct 82° 51°
- Nov 69° 39°
- Dec 59° 31°
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 San Carlos each month?
July is the warmest month, with normal highs of 99°F; December the coldest, with normal lows of 31°F. The most precipitation falls in January (1.88 in), the least in June (0.14 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 59°F | 31°F | 45.2°F | 1.88 | 5 | <1 | 14 | 10 h 10 min |
| February | 63°F | 35°F | 49.1°F | 1.70 | 5 | <1 | 7 | 11 h |
| March | 70°F | 39°F | 54.7°F | 1.21 | 4 | <1 | 2 | 12 h |
| April | 78°F | 47°F | 62.5°F | 0.41 | 2 | 4 | 1 | 13 h |
| May | 88°F | 56°F | 71.9°F | 0.46 | 2 | 17 | <1 | 13 h 50 min |
| June | 98°F | 65°F | 81.4°F | 0.14 | 1 | 28 | <1 | 14 h 20 min |
| July | 99°F | 71°F | 84.7°F | 1.62 | 6 | 29 | <1 | 14 h 10 min |
| August | 97°F | 70°F | 83.5°F | 1.77 | 7 | 28 | <1 | 13 h 30 min |
| September | 93°F | 63°F | 77.7°F | 1.12 | 5 | 22 | <1 | 12 h 30 min |
| October | 82°F | 51°F | 66.7°F | 0.85 | 3 | 9 | <1 | 11 h 20 min |
| November | 69°F | 39°F | 53.7°F | 0.88 | 3 | <1 | 4 | 10 h 30 min |
| December | 59°F | 31°F | 44.9°F | 1.38 | 5 | <1 | 15 | 10 h |
| Year (annual) | 80°F | 50°F | 64.7°F | 13.42 | 48 | 138 | 42 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 15°C | 0°C | 7.3°C | 48 mm |
| February | 17°C | 2°C | 9.5°C | 43 mm |
| March | 21°C | 4°C | 12.6°C | 31 mm |
| April | 26°C | 8°C | 16.9°C | 10 mm |
| May | 31°C | 13°C | 22.2°C | 12 mm |
| June | 37°C | 18°C | 27.4°C | 4 mm |
| July | 37°C | 22°C | 29.3°C | 41 mm |
| August | 36°C | 21°C | 28.6°C | 45 mm |
| September | 34°C | 17°C | 25.4°C | 28 mm |
| October | 28°C | 11°C | 19.3°C | 22 mm |
| November | 20°C | 4°C | 12.1°C | 22 mm |
| December | 15°C | 0°C | 7.2°C | 35 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00027480; 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 San Carlos?
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 USC00027480.
When is the last frost in San Carlos?
In San Carlos, the last spring frost (32°F) comes after March 13 in half of years and after April 6 in one year in ten; the first autumn frost comes before November 19 in half of years and before November 3 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
- March 131 year in 10 after April 6; 9 in 10 after February 17
- First autumn frost, half of years before
- November 191 year in 10 before November 3; 9 in 10 before December 4
NOAA puts the median frost-free season at 247 days, and the season without a hard freeze (28°F) at 284 days.
A hard freeze (28°F) comes after February 17 in half of springs and before December 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts San Carlos in zone 9a in ZIP code 85542, 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 USC00027480; 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 San Carlos?
In a normal year in San Carlos, 138 days a year reach 90°F (59 of them 100°F or more), 42 nights fall to 32°F or colder and 48 days bring measurable precipitation.
- Days at 90°F or more
- 138a normal year
- Days at 100°F or more
- 59a normal year
- Nights at 32°F or colder
- 42a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 48a normal year
The highest temperature in this station's record (since 1900) is 116°F, on June 30, 1994; the lowest is 11°F, on January 8, 1971.
The wettest calendar year on that record is 1978, with 29.31 in; the snowiest season is 1984–85, with 9.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00027480; records: ACIS (NOAA Regional Climate Centers), station USC00027480. Records use complete months only; a month missing more than three days is left out.
How sunny is San Carlos?
Over a year 89% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around San Carlos, 5.7 kWh per square metre a day. June is the sunniest month (95%) and December the cloudiest (83%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 84% | 3.4 |
| February | 83% | 4.3 |
| March | 88% | 5.8 |
| April | 91% | 7.2 |
| May | 93% | 8.1 |
| June | 95% | 8.4 |
| July | 84% | 7.0 |
| August | 87% | 6.6 |
| September | 89% | 5.9 |
| October | 91% | 4.9 |
| November | 88% | 3.8 |
| December | 83% | 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 San Carlos need?
A normal year in San Carlos brings 2,566 heating degree days, 52% fewer than the median U.S. place (5,373), and 2,479 cooling degree days, 2.7 times the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 5,890 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 614 | 0 |
| February | 444 | 0 |
| March | 321 | 3 |
| April | 127 | 51 |
| May | 21 | 237 |
| June | 1 | 493 |
| July | 0 | 611 |
| August | 0 | 575 |
| September | 5 | 387 |
| October | 68 | 120 |
| November | 344 | 3 |
| December | 623 | 0 |
| Year (annual) | 2,566 | 2,479 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00027480. 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 San Carlos's climate compare?
San Carlos is warmer than 48 of the other 96 places with their own NOAA record in Arizona, and wetter than 62. Across the 7,247 U.S. stations with normals, its annual mean of 64.7°F is warmer than 87%.
In the Köppen classification computed from these normals, San Carlos 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 San Carlos share this climate record?
4 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.
- Peridot, AZ1,141 people · 9 mi NE
- Hayden, AZ513 people · 20 mi SW
- Winkelman, AZ295 people · 19 mi SW
- Dripping Springs, AZ277 people · 14 mi W
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 San Carlos's climate
What is the coldest month in San Carlos?
December, with a normal high of 59°F and a normal low of 31°F. The warmest is July (99°F by day, 71°F at night).
Does it snow in San Carlos?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month in San Carlos?
January, with 1.88 in of precipitation in a normal year; the driest is June with 0.14 in.
What plant hardiness zone is San Carlos in?
The USDA's 2023 map puts San Carlos in zone 9a in ZIP code 85542, the nearest ZIP area.
How late can frost come in San Carlos?
In half of years the last 32°F night comes after March 13; in one year in ten it comes after April 6. Waiting until April 6 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Arizona climateThe statewide normals and every place in the state
- Globe, AZ21 miles from this station, 63.6°F a year
- Miami, AZ25 miles from this station, 66.8°F a year
- Fort Thomas, AZ34 miles from this station, 64.5°F a year
- Superior, AZ34 miles from this station, 70.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made