Green Valley, Arizona climate: Normal weather by month, frost dates and records
Green Valley's normal year runs from 36°F December nights to 99°F July afternoons, with 12.8 inches of precipitation and less than an inch of snow (0.1 in) a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 20.2°C, December lows of 2°C, July highs of 37°C, 326 mm of precipitation a year.
- NOAA stationGreen Valley
- Station IDUSC00023668
- Location31.89°N 111.00°W
- Elevation2,900 ft (884 m)
- Population (census place)21,581
On October 23, the normal high in Green Valley is 85°F and the normal low 51°F, and the chance of measurable rain or snow is 10%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Green Valley.
- Jan 67° 36°
- Feb 69° 39°
- Mar 76° 44°
- Apr 82° 50°
- May 91° 58°
- Jun 100° 68°
- Jul 99° 72°
- Aug 97° 71°
- Sep 94° 66°
- Oct 87° 54°
- Nov 76° 43°
- Dec 66° 36°
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 Green Valley each month?
July is the warmest month, with normal highs of 99°F; December the coldest, with normal lows of 36°F. The most precipitation falls in July (2.86 in), the least in May (0.18 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 67°F | 36°F | 51.5°F | 0.78 | 4 | <1 | 7 | 10 h 20 min |
| February | 69°F | 39°F | 54.2°F | 0.86 | 4 | <1 | 4 | 11 h |
| March | 76°F | 44°F | 60.0°F | 0.58 | 3 | 1 | 1 | 12 h |
| April | 82°F | 50°F | 66.1°F | 0.27 | 2 | 6 | <1 | 13 h |
| May | 91°F | 58°F | 74.5°F | 0.18 | 1 | 19 | <1 | 13 h 50 min |
| June | 100°F | 68°F | 83.8°F | 0.44 | 2 | 29 | <1 | 14 h 10 min |
| July | 99°F | 72°F | 85.4°F | 2.86 | 10 | 29 | <1 | 14 h |
| August | 97°F | 71°F | 84.2°F | 2.69 | 10 | 29 | <1 | 13 h 20 min |
| September | 94°F | 66°F | 80.4°F | 1.70 | 5 | 26 | <1 | 12 h 20 min |
| October | 87°F | 54°F | 70.4°F | 0.84 | 3 | 12 | <1 | 11 h 30 min |
| November | 76°F | 43°F | 59.5°F | 0.51 | 2 | 1 | 2 | 10 h 30 min |
| December | 66°F | 36°F | 51.2°F | 1.14 | 4 | <1 | 9 | 10 h |
| Year (annual) | 84°F | 53°F | 68.4°F | 12.85 | 51 | 151 | 24 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 19°C | 2°C | 10.8°C | 20 mm |
| February | 21°C | 4°C | 12.3°C | 22 mm |
| March | 24°C | 7°C | 15.6°C | 15 mm |
| April | 28°C | 10°C | 18.9°C | 7 mm |
| May | 33°C | 15°C | 23.6°C | 5 mm |
| June | 38°C | 20°C | 28.8°C | 11 mm |
| July | 37°C | 22°C | 29.7°C | 73 mm |
| August | 36°C | 22°C | 29.0°C | 68 mm |
| September | 35°C | 19°C | 26.9°C | 43 mm |
| October | 30°C | 12°C | 21.3°C | 21 mm |
| November | 24°C | 6°C | 15.3°C | 13 mm |
| December | 19°C | 2°C | 10.7°C | 29 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00023668; 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 Green Valley?
Normal highs sit between 65°F and 85°F in January, February, March, April, November and December. 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 USC00023668.
When is the last frost in Green Valley?
In Green Valley, the last spring frost (32°F) comes after February 25 in half of years and after March 18 in one year in ten; the first autumn frost comes before November 27 in half of years and before November 12 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
- February 251 year in 10 after March 18; 9 in 10 after January 31
- First autumn frost, half of years before
- November 271 year in 10 before November 12; 9 in 10 before December 13
NOAA puts the median frost-free season at 276 days, and the season without a hard freeze (28°F) at 316 days.
A hard freeze (28°F) comes after February 1 in half of springs and before December 10 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Green Valley in zone 9a in ZIP code 85614, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Green Valley's NOAA station is in zone 9a: the coldest night of a typical year reaches 24°F (17 complete years).
Frost dates for every NOAA station in Arizona · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00023668; 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 Green Valley?
In a normal year in Green Valley, 151 days a year reach 90°F (54 of them 100°F or more), 24 nights fall to 32°F or colder and 51 days bring measurable precipitation.
- Days at 90°F or more
- 151a normal year
- Days at 100°F or more
- 54a normal year
- Nights at 32°F or colder
- 24a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 51a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00023668.
How sunny is Green Valley?
Over a year 89% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Green Valley, 5.8 kWh per square metre a day. May is the sunniest month (94%) and July the cloudiest (79%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 87% | 3.8 |
| February | 87% | 4.7 |
| March | 90% | 6.2 |
| April | 94% | 7.6 |
| May | 94% | 8.3 |
| June | 92% | 8.1 |
| July | 79% | 6.5 |
| August | 83% | 6.3 |
| September | 87% | 5.8 |
| October | 92% | 5.2 |
| November | 90% | 4.1 |
| December | 87% | 3.5 |
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 Green Valley need?
A normal year in Green Valley brings 1,631 heating degree days, 70% fewer than the median U.S. place (5,373), and 2,909 cooling degree days, 3.2 times the median (908). Three months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 6,939 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 419 | 0 |
| February | 307 | 3 |
| March | 182 | 27 |
| April | 65 | 96 |
| May | 8 | 303 |
| June | 0 | 564 |
| July | 0 | 634 |
| August | 0 | 595 |
| September | 0 | 462 |
| October | 27 | 194 |
| November | 195 | 30 |
| December | 428 | 1 |
| Year (annual) | 1,631 | 2,909 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00023668. 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 Green Valley been warmer than normal lately?
2024 averaged 69.6°F, 1.2°F above the 1991-2020 normal of 68.4°F. 1 of the 2 complete years since 2022 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2022 | 67.8°F | −0.6°F | 15.74 |
| 2024 | 69.6°F | +1.2°F | 11.12 |
Source: observed years: ACIS, station USC00023668. A year counts only with all twelve months complete.
How does Green Valley's climate compare?
Green Valley is warmer than 61 of the other 96 places with their own NOAA record in Arizona, and wetter than 56. Across the 7,247 U.S. stations with normals, its annual mean of 68.4°F is warmer than 94%.
In the Köppen classification computed from these normals, Green Valley 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 Green Valley 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.
- Sahuarita, AZ37,448 people · 3 mi NE
- Corona de Tucson, AZ9,039 people · 13 mi E
- Arivaca Junction, AZ650 people · 12 mi SW
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 Green Valley's climate
What is the coldest month in Green Valley?
December, with a normal high of 66°F and a normal low of 36°F. The warmest is July (99°F by day, 72°F at night).
Does it snow in Green Valley?
Rarely: NOAA's normal is 0.1 inch a year.
What is the rainiest month in Green Valley?
July, with 2.86 in of precipitation in a normal year; the driest is May with 0.18 in.
What plant hardiness zone is Green Valley in?
The USDA's 2023 map puts Green Valley in zone 9a in ZIP code 85614, the nearest ZIP area. By the same method at Green Valley's NOAA station, the coldest night of a typical year reaches 24°F (17 years, 1991-2020): zone 9a.
How late can frost come in Green Valley?
In half of years the last 32°F night comes after February 25; in one year in ten it comes after March 18. Waiting until March 18 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Arizona climateThe statewide normals and every place in the state
- Santa Rita Experiment Range, AZ12 miles from this station, 65.3°F a year
- Tucson, AZ17 miles from this station, 70.6°F a year
- Tumacacori National Monument, AZ23 miles from this station, 63.0°F a year
- Anvil Ranch, AZ24 miles from this station, 66.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made