USDA Hardiness Zone 9b
Frost Dates for 85337 — Gila Bend, Arizona
NOAA 1991–2020 normals from Gila Bend 2SE, AZ (794 ft), 7 miles east.
Updated
In Gila Bend, the last spring frost (32°F) is around January 23 in half of years and has passed by February 19 in nine years out of ten. The first fall frost comes around December 11, as early as November 24 one year in ten, leaving a typical freeze-free season of 323 days (NOAA, Gila Bend 2SE, AZ).
- Last spring frost
- January 23
- First fall frost
- December 11
- Growing season
- 323 days
- Hardiness zone
- 9b
50% probability
50% probability
freeze-free, 50%
25 to 30°F (-3.9 to -1.1°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 0%
- Snow per year
- 0"
median, 1991–2020
median, 1991–2020
0 of 21 observed
NOAA normal
Frost risk by date in Gila Bend
Half of springs at Gila Bend 2SE, AZ see their last 32°F night by January 23; only one in ten is past it by December 25, and one in ten still has one after February 19. Planting tender crops after February 2 leaves a 30% risk of a frost on them, after February 8 20%, and after February 19 10%. The 27 days between the even-odds date and the one-in-ten date is wider than at 71% of the 98 Arizona stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.
In fall the first 32°F night comes by December 11 in half of years, as early as November 24 one year in ten, and holds off past December 30 one year in ten. A hard freeze of 28°F follows 14 days later, around December 25; in spring the one-in-ten date for 28°F is February 1, 18 days before the 32°F one. The freeze-free season lasts 323 days in a typical year, longer than at 83% of the 98 Arizona stations; it reaches 352 days one year in ten and falls short of 293 one year in ten. On average 10 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 22 days longer, to about February 14, and return around November 30. A 24°F night is unusual: 20% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jan 18 | Jan 27 | Feb 2 | Feb 8 | Feb 14 | Feb 19 | Feb 24 | Feb 28 | Mar 5 |
| 32°F97% of yrs | Dec 25 | Jan 3 | Jan 11 | Jan 17 | Jan 23 | Jan 29 | Feb 2 | Feb 8 | Feb 19 |
| 28°F69% of yrs | Dec 13 | Dec 21 | Dec 27 | Dec 31 | Jan 5 | Jan 11 | Jan 16 | Jan 24 | Feb 1 |
| 24°F20% of yrs | too rare for a date | ||||||||
| 20°F3% of yrs | too rare for a date | ||||||||
| 16°F0% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 15 | Nov 20 | Nov 23 | Nov 26 | Nov 30 | Dec 2 | Dec 5 | Dec 10 | Dec 15 |
| 32°F97% of yrs | Nov 24 | Nov 30 | Dec 3 | Dec 7 | Dec 11 | Dec 15 | Dec 18 | Dec 22 | Dec 30 |
| 28°F69% of yrs | Dec 5 | Dec 11 | Dec 15 | Dec 20 | Dec 25 | Dec 29 | Jan 1 | Jan 9 | Jan 22 |
| 24°F20% of yrs | too rare for a date | ||||||||
| 20°F3% of yrs | too rare for a date | ||||||||
| 16°F0% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Gila Bend 2SE, AZ, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 85337 →Compare Gila Bend with another place →
Weather by month in Gila Bend
July is the warmest month at Gila Bend 2SE, AZ, averaging 109°F by day and 81°F at night; December is the coldest at 70°F and 40°F. From March to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 32% of years.
Warmth for growing adds up to 9,081 growing degree days a year (base 50°F), more than at 97% of the 102 Arizona stations. 41% of them (3,743) have built up by the end of June, and July adds the most, 1,393. Precipitation totals 6.5 inches a year, most in February (0.9") and least in June (0.1"); May to September bring 35% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 71 | 41 | 0.8 | 73% | 3 | 206 |
| Feb | 75 | 44 | 0.9 | 32% | 1 | 270 |
| Mar | 82 | 49 | 0.7 | 2% | 0 | 482 |
| Apr | 90 | 55 | 0.3 | 0% | 0 | 663 |
| May | 98 | 63 | 0.4 | 0% | 0 | 938 |
| Jun | 107 | 72 | 0.1 | 0% | 0 | 1185 |
| Jul | 109 | 81 | 0.6 | 0% | 0 | 1393 |
| Aug | 109 | 81 | 0.9 | 0% | 0 | 1383 |
| Sep | 104 | 74 | 0.3 | 0% | 0 | 1159 |
| Oct | 93 | 60 | 0.4 | 0% | 0 | 822 |
| Nov | 80 | 48 | 0.5 | 20% | 1 | 416 |
| Dec | 70 | 40 | 0.6 | 86% | 5 | 165 |
Monthly normals 1991–2020 at Gila Bend 2SE, AZ (794 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Painted Rock Dam, AZ, 16 miles northwest of Gila Bend and 226 feet lower, has a last frost 2 days earlier (January 21), a first frost 4 days later (December 15), a season 4 days longer.
When it snows in Gila Bend, Arizona
Measurable snow is rare here: only 0 of 21 winters from 1991 to 2020 recorded 0.1 inch or more at Gila Bend 2SE, AZ, 7 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 85337
| When | What to do |
|---|---|
| November 14 – November 28 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| November 28 – December 12 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| December 26 – January 9 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| January 23 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 18 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 27 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| December 11 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 85337 is 7 miles from Gila Bend 2SE, AZ, which stands at 794 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 85337 in zone 9b, the band where the coldest night of the year averaged 25 to 30°F (-3.9 to -1.1°C) over 1991–2020; a zone describes winter lows, not frost dates.
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.