Last spring frost
May 17
Frost Dates for Crozier, AZ
First fall frost
Oct 10
Growing season
146 days
Hardiness zone
8a
In an average year around Crozier, AZ, the last spring frost (32°F) is about May 17 and the first fall frost is about Oct 10, giving roughly a 146-day growing season. To be safe most years, wait until May 1 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Jun 16 | Jun 2 | May 16 |
| Freeze (32°F) | Jun 4 | May 17 | May 1 |
| Hard (28°F) | May 17 | Apr 30 | Apr 11 |
| Severe (24°F) | May 1 | Apr 9 | Mar 16 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 16 | Jun 10 | Jun 7 | Jun 5 | Jun 2 | May 31 | May 28 | May 22 | May 16 |
| 32°F | Jun 4 | May 31 | May 25 | May 20 | May 17 | May 14 | May 9 | May 5 | May 1 |
| 28°F | May 17 | May 11 | May 5 | May 2 | Apr 30 | Apr 27 | Apr 23 | Apr 18 | Apr 11 |
| 24°F | May 1 | Apr 24 | Apr 20 | Apr 14 | Apr 9 | Apr 5 | Mar 31 | Mar 25 | Mar 16 |
| 20°F | Apr 10 | Apr 2 | Mar 28 | Mar 21 | Mar 15 | Mar 10 | Mar 6 | Mar 2 | Feb 22 |
| 16°F | Mar 27 | Mar 12 | Mar 6 | Mar 2 | Feb 26 | Feb 20 | Feb 13 | Feb 5 | Jan 23 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Sep 20 | Oct 1 | Oct 15 |
| Freeze (32°F) | Sep 28 | Oct 10 | Oct 26 |
| Hard (28°F) | Oct 8 | Oct 23 | Nov 8 |
| Severe (24°F) | Oct 18 | Nov 6 | Nov 20 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 20 | Sep 24 | Sep 27 | Sep 29 | Oct 1 | Oct 4 | Oct 6 | Oct 9 | Oct 15 |
| 32°F | Sep 28 | Oct 2 | Oct 5 | Oct 7 | Oct 10 | Oct 14 | Oct 16 | Oct 20 | Oct 26 |
| 28°F | Oct 8 | Oct 13 | Oct 16 | Oct 20 | Oct 23 | Oct 27 | Oct 31 | Nov 4 | Nov 8 |
| 24°F | Oct 18 | Oct 24 | Oct 30 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 16 | Nov 20 |
| 20°F | Nov 1 | Nov 7 | Nov 12 | Nov 16 | Nov 19 | Nov 21 | Nov 24 | Nov 28 | Dec 4 |
| 16°F | Nov 13 | Nov 19 | Nov 23 | Nov 27 | Dec 1 | Dec 4 | Dec 8 | Dec 13 | Dec 20 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Diamond M Rch, Az, about 14.8 miles away@if(!empty($station['elevation_ft'])), at 5,492 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Crozier, AZ?
On average, the last spring frost (32°F) around Crozier, AZ is about May 17. In cooler years it can run later, so for a safer bet many gardeners wait until May 1.
When is the first frost in the fall?
The first fall frost around Crozier, AZ typically arrives about Oct 10. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around May 17 on average, or May 1 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 146 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 86437 Planting calendar → Arizona frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026