Last spring frost
Apr 5
Frost Dates for Sierra Vista Southeast, AZ
First fall frost
Nov 9
Growing season
216 days
Hardiness zone
8b
In an average year around Sierra Vista Southeast, AZ, the last spring frost (32°F) is about Apr 5 and the first fall frost is about Nov 9, giving roughly a 216-day growing season. To be safe most years, wait until Mar 15 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 20 | Apr 5 |
| Freeze (32°F) | Apr 21 | Apr 5 | Mar 15 |
| Hard (28°F) | Apr 5 | Mar 15 | Feb 21 |
| Severe (24°F) | Mar 15 | Feb 19 | Jan 20 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 4 | Apr 30 | Apr 27 | Apr 23 | Apr 20 | Apr 16 | Apr 13 | Apr 9 | Apr 5 |
| 32°F | Apr 21 | Apr 15 | Apr 11 | Apr 8 | Apr 5 | Apr 2 | Mar 30 | Mar 24 | Mar 15 |
| 28°F | Apr 5 | Mar 31 | Mar 25 | Mar 20 | Mar 15 | Mar 10 | Mar 7 | Feb 28 | Feb 21 |
| 24°F | Mar 15 | Mar 6 | Mar 1 | Feb 24 | Feb 19 | Feb 14 | Feb 7 | Jan 31 | Jan 20 |
| 20°F | Feb 20 | Feb 12 | Feb 5 | Jan 31 | Jan 24 | Jan 15 | Jan 9 | Jan 3 | Dec 25 |
| 16°F | Feb 8 | Feb 2 | Jan 25 | Jan 17 | Jan 9 | Jan 4 | Dec 31 | Dec 24 | Dec 15 |
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 15 | Oct 30 | Nov 12 |
| Freeze (32°F) | Oct 23 | Nov 9 | Nov 23 |
| Hard (28°F) | Nov 4 | Nov 21 | Dec 5 |
| Severe (24°F) | Nov 16 | Dec 3 | Dec 21 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 15 | Oct 20 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 12 |
| 32°F | Oct 23 | Oct 29 | Nov 2 | Nov 5 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 23 |
| 28°F | Nov 4 | Nov 10 | Nov 15 | Nov 18 | Nov 21 | Nov 24 | Nov 27 | Dec 1 | Dec 5 |
| 24°F | Nov 16 | Nov 22 | Nov 26 | Nov 30 | Dec 3 | Dec 6 | Dec 10 | Dec 15 | Dec 21 |
| 20°F | Nov 28 | Dec 4 | Dec 10 | Dec 15 | Dec 20 | Dec 24 | Dec 29 | Jan 4 | Jan 17 |
| 16°F | Dec 7 | Dec 16 | Dec 23 | Dec 28 | Jan 1 | Jan 4 | Jan 10 | Jan 22 | Feb 3 |
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: Sierra Vista, Az, about 5.4 miles away@if(!empty($station['elevation_ft'])), at 4,606 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 5. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 15.
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 5 on average, or Mar 15 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 216 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 85650 Planting calendar → Arizona frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026