Last spring frost
Apr 11
Frost Dates for Halchita, AZ
First fall frost
Oct 30
Growing season
201 days
Hardiness zone
7b
In an average year around Halchita, AZ, the last spring frost (32°F) is about Apr 11 and the first fall frost is about Oct 30, giving roughly a 201-day growing season. To be safe most years, wait until Mar 27 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) | May 4 | Apr 23 | Apr 9 |
| Freeze (32°F) | Apr 26 | Apr 11 | Mar 27 |
| Hard (28°F) | Apr 16 | Mar 30 | Mar 9 |
| Severe (24°F) | Apr 6 | Mar 9 | Feb 15 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 4 | Apr 30 | Apr 28 | Apr 25 | Apr 23 | Apr 20 | Apr 17 | Apr 14 | Apr 9 |
| 32°F | Apr 26 | Apr 20 | Apr 17 | Apr 13 | Apr 11 | Apr 8 | Apr 5 | Apr 2 | Mar 27 |
| 28°F | Apr 16 | Apr 9 | Apr 5 | Apr 2 | Mar 30 | Mar 25 | Mar 19 | Mar 14 | Mar 9 |
| 24°F | Apr 6 | Mar 29 | Mar 19 | Mar 13 | Mar 9 | Mar 5 | Mar 1 | Feb 25 | Feb 15 |
| 20°F | Mar 18 | Mar 7 | Mar 1 | Feb 26 | Feb 20 | Feb 14 | Feb 8 | Feb 2 | Jan 26 |
| 16°F | Feb 28 | Feb 19 | Feb 12 | Feb 6 | Feb 1 | Jan 28 | Jan 20 | Jan 11 | Jan 1 |
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) | Oct 6 | Oct 20 | Nov 1 |
| Freeze (32°F) | Oct 17 | Oct 30 | Nov 11 |
| Hard (28°F) | Oct 27 | Nov 8 | Nov 21 |
| Severe (24°F) | Nov 5 | Nov 18 | Dec 1 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 6 | Oct 11 | Oct 14 | Oct 18 | Oct 20 | Oct 22 | Oct 25 | Oct 28 | Nov 1 |
| 32°F | Oct 17 | Oct 22 | Oct 25 | Oct 28 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 11 |
| 28°F | Oct 27 | Nov 1 | Nov 3 | Nov 6 | Nov 8 | Nov 11 | Nov 14 | Nov 17 | Nov 21 |
| 24°F | Nov 5 | Nov 10 | Nov 13 | Nov 16 | Nov 18 | Nov 21 | Nov 23 | Nov 26 | Dec 1 |
| 20°F | Nov 15 | Nov 20 | Nov 23 | Nov 26 | Nov 28 | Dec 1 | Dec 4 | Dec 8 | Dec 14 |
| 16°F | Nov 25 | Nov 30 | Dec 3 | Dec 7 | Dec 11 | Dec 15 | Dec 20 | Dec 26 | Jan 1 |
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: Mexican Hat, Ut, about 6.5 miles away@if(!empty($station['elevation_ft'])), at 4,109 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 Halchita, AZ?
On average, the last spring frost (32°F) around Halchita, AZ is about Apr 11. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 27.
When is the first frost in the fall?
The first fall frost around Halchita, AZ typically arrives about Oct 30. 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 Apr 11 on average, or Mar 27 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 201 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 84531 Planting calendar → Arizona frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026