Last spring frost
Feb 26
Frost Dates for Morenci, AZ
First fall frost
Nov 23
Growing season
268 days
Hardiness zone
8a
In an average year around Morenci, AZ, the last spring frost (32°F) is about Feb 26 and the first fall frost is about Nov 23, giving roughly a 268-day growing season. To be safe most years, wait until Feb 6 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) | Apr 7 | Mar 14 | Feb 24 |
| Freeze (32°F) | Mar 15 | Feb 26 | Feb 6 |
| Hard (28°F) | Mar 3 | Feb 5 | Jan 9 |
| Severe (24°F) | Feb 9 | Jan 15 | Dec 17 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 7 | Mar 31 | Mar 24 | Mar 18 | Mar 14 | Mar 10 | Mar 6 | Mar 2 | Feb 24 |
| 32°F | Mar 15 | Mar 10 | Mar 6 | Mar 2 | Feb 26 | Feb 22 | Feb 17 | Feb 12 | Feb 6 |
| 28°F | Mar 3 | Feb 22 | Feb 15 | Feb 9 | Feb 5 | Feb 1 | Jan 29 | Jan 21 | Jan 9 |
| 24°F | Feb 9 | Feb 2 | Jan 30 | Jan 23 | Jan 15 | Jan 9 | Jan 4 | Dec 28 | Dec 17 |
| 20°F | Feb 2 | Jan 30 | Jan 19 | Jan 12 | Jan 8 | Jan 4 | Dec 30 | Dec 22 | Dec 13 |
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 30 | Nov 14 | Nov 25 |
| Freeze (32°F) | Nov 10 | Nov 23 | Dec 6 |
| Hard (28°F) | Nov 20 | Dec 5 | Dec 24 |
| Severe (24°F) | Nov 28 | Dec 20 | Jan 16 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 30 | Nov 4 | Nov 8 | Nov 11 | Nov 14 | Nov 16 | Nov 19 | Nov 21 | Nov 25 |
| 32°F | Nov 10 | Nov 15 | Nov 18 | Nov 21 | Nov 23 | Nov 26 | Nov 28 | Dec 1 | Dec 6 |
| 28°F | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 5 | Dec 9 | Dec 13 | Dec 18 | Dec 24 |
| 24°F | Nov 28 | Dec 6 | Dec 12 | Dec 16 | Dec 20 | Dec 25 | Dec 29 | Jan 5 | Jan 16 |
| 20°F | Dec 6 | Dec 18 | Dec 24 | Dec 30 | Jan 3 | Jan 6 | Jan 11 | Jan 20 | Jan 30 |
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: Clifton, Az, about 16.5 miles away@if(!empty($station['elevation_ft'])), at 3,520 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 Morenci, AZ?
On average, the last spring frost (32°F) around Morenci, AZ is about Feb 26. In cooler years it can run later, so for a safer bet many gardeners wait until Feb 6.
When is the first frost in the fall?
The first fall frost around Morenci, AZ typically arrives about Nov 23. 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 Feb 26 on average, or Feb 6 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 268 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 85533 Planting calendar → Arizona frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026