Last spring frost
Apr 1
Frost Dates for Naco, AZ
First fall frost
Nov 10
Growing season
222 days
Hardiness zone
8b
In an average year around Naco, AZ, the last spring frost (32°F) is about Apr 1 and the first fall frost is about Nov 10, giving roughly a 222-day growing season. To be safe most years, wait until Mar 13 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 18 | Apr 3 |
| Freeze (32°F) | Apr 20 | Apr 1 | Mar 13 |
| Hard (28°F) | Apr 4 | Mar 13 | Feb 16 |
| Severe (24°F) | Mar 16 | Feb 14 | Jan 12 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 4 | Apr 29 | Apr 25 | Apr 21 | Apr 18 | Apr 15 | Apr 12 | Apr 8 | Apr 3 |
| 32°F | Apr 20 | Apr 13 | Apr 8 | Apr 4 | Apr 1 | Mar 29 | Mar 25 | Mar 20 | Mar 13 |
| 28°F | Apr 4 | Mar 29 | Mar 23 | Mar 17 | Mar 13 | Mar 8 | Mar 4 | Feb 27 | Feb 16 |
| 24°F | Mar 16 | Mar 7 | Mar 1 | Feb 21 | Feb 14 | Feb 7 | Feb 1 | Jan 23 | Jan 12 |
| 20°F | Feb 22 | Feb 13 | Feb 3 | Jan 29 | Jan 20 | Jan 12 | Jan 5 | Dec 29 | Dec 14 |
| 16°F | Feb 13 | Feb 4 | Jan 27 | Jan 17 | Jan 10 | Jan 4 | Dec 31 | Dec 18 | Dec 4 |
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 17 | Oct 30 | Nov 14 |
| Freeze (32°F) | Oct 25 | Nov 10 | Nov 28 |
| Hard (28°F) | Nov 5 | Nov 24 | Dec 13 |
| Severe (24°F) | Nov 13 | Dec 6 | Jan 1 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 17 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 8 | Nov 14 |
| 32°F | Oct 25 | Oct 31 | Nov 3 | Nov 6 | Nov 10 | Nov 14 | Nov 18 | Nov 23 | Nov 28 |
| 28°F | Nov 5 | Nov 11 | Nov 16 | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 6 | Dec 13 |
| 24°F | Nov 13 | Nov 21 | Nov 26 | Dec 2 | Dec 6 | Dec 10 | Dec 15 | Dec 21 | Jan 1 |
| 20°F | Nov 24 | Dec 3 | Dec 10 | Dec 19 | Dec 24 | Dec 30 | Jan 4 | Jan 13 | Jan 28 |
| 16°F | Nov 27 | Dec 12 | Dec 23 | Dec 31 | Jan 3 | Jan 10 | Jan 18 | Jan 28 | Feb 9 |
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: Bisbee 1Wnw, Az, about 7.6 miles away@if(!empty($station['elevation_ft'])), at 5,560 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 Naco, AZ?
On average, the last spring frost (32°F) around Naco, AZ is about Apr 1. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 13.
When is the first frost in the fall?
The first fall frost around Naco, AZ typically arrives about Nov 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 Apr 1 on average, or Mar 13 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 222 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 85620 Planting calendar → Arizona frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026