Last spring frost
Apr 7
Frost Dates for Sierra Vista Southeast, AZ
First fall frost
Nov 9
Growing season
213 days
Hardiness zone
8b
In an average year around Sierra Vista Southeast, AZ, the last spring frost (32°F) is about Apr 7 and the first fall frost is about Nov 9, giving roughly a 213-day growing season. To be safe most years, wait until Mar 19 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 12 | Apr 24 | Apr 5 |
| Freeze (32°F) | Apr 27 | Apr 7 | Mar 19 |
| Hard (28°F) | Apr 12 | Mar 19 | Feb 22 |
| Severe (24°F) | Mar 25 | Feb 22 | Jan 23 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 12 | May 5 | May 1 | Apr 28 | Apr 24 | Apr 21 | Apr 16 | Apr 12 | Apr 5 |
| 32°F | Apr 27 | Apr 20 | Apr 15 | Apr 11 | Apr 7 | Apr 4 | Mar 31 | Mar 27 | Mar 19 |
| 28°F | Apr 12 | Apr 4 | Mar 30 | Mar 24 | Mar 19 | Mar 13 | Mar 7 | Mar 1 | Feb 22 |
| 24°F | Mar 25 | Mar 12 | Mar 6 | Feb 28 | Feb 22 | Feb 16 | Feb 10 | Feb 3 | Jan 23 |
| 20°F | Feb 26 | Feb 17 | Feb 11 | Feb 5 | Jan 31 | Jan 23 | Jan 13 | Jan 4 | Dec 26 |
| 16°F | Feb 14 | Feb 7 | Feb 1 | Jan 27 | Jan 19 | Jan 10 | Jan 3 | Dec 29 | Dec 21 |
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 16 | Oct 31 | Nov 14 |
| Freeze (32°F) | Oct 25 | Nov 9 | Nov 27 |
| Hard (28°F) | Nov 1 | Nov 20 | Dec 7 |
| Severe (24°F) | Nov 13 | Dec 4 | Dec 26 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 16 | Oct 21 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 9 | Nov 14 |
| 32°F | Oct 25 | Oct 30 | Nov 2 | Nov 5 | Nov 9 | Nov 12 | Nov 16 | Nov 20 | Nov 27 |
| 28°F | Nov 1 | Nov 8 | Nov 12 | Nov 16 | Nov 20 | Nov 24 | Nov 28 | Dec 3 | Dec 7 |
| 24°F | Nov 13 | Nov 20 | Nov 26 | Nov 30 | Dec 4 | Dec 7 | Dec 13 | Dec 19 | Dec 26 |
| 20°F | Nov 28 | Dec 7 | Dec 13 | Dec 19 | Dec 23 | Dec 28 | Jan 3 | Jan 13 | Jan 28 |
| 16°F | Dec 15 | Dec 22 | Dec 28 | Jan 1 | Jan 7 | Jan 16 | Jan 23 | Jan 31 | Feb 10 |
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: Coronado Nmem, Az, about 4.4 miles away@if(!empty($station['elevation_ft'])), at 5,242 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 Sierra Vista Southeast, AZ?
On average, the last spring frost (32°F) around Sierra Vista Southeast, AZ is about Apr 7. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 19.
When is the first frost in the fall?
The first fall frost around Sierra Vista Southeast, AZ typically arrives about Nov 9. 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 7 on average, or Mar 19 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 213 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 85615 Planting calendar → Arizona frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026