Last spring frost
Feb 17
Frost Dates for Coolidge, AZ
First fall frost
Nov 29
Growing season
284 days
Hardiness zone
9a
In an average year around Coolidge, AZ, the last spring frost (32°F) is about Feb 17 and the first fall frost is about Nov 29, giving roughly a 284-day growing season. To be safe most years, wait until Jan 22 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 5 | Mar 8 | Feb 16 |
| Freeze (32°F) | Mar 8 | Feb 17 | Jan 22 |
| Hard (28°F) | Feb 23 | Jan 26 | Dec 26 |
| Severe (24°F) | Feb 4 | Jan 7 | Dec 13 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 5 | Mar 27 | Mar 19 | Mar 13 | Mar 8 | Mar 4 | Mar 1 | Feb 25 | Feb 16 |
| 32°F | Mar 8 | Mar 3 | Feb 28 | Feb 22 | Feb 17 | Feb 11 | Feb 6 | Jan 31 | Jan 22 |
| 28°F | Feb 23 | Feb 15 | Feb 6 | Feb 2 | Jan 26 | Jan 19 | Jan 11 | Jan 3 | Dec 26 |
| 24°F | Feb 4 | Jan 27 | Jan 18 | Jan 11 | Jan 7 | Jan 3 | Dec 31 | Dec 23 | Dec 13 |
| 20°F | Jan 27 | Jan 19 | Jan 11 | Jan 8 | Jan 5 | Jan 2 | Jan 1 | Dec 31 | Dec 22 |
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) | Nov 4 | Nov 19 | Dec 3 |
| Freeze (32°F) | Nov 12 | Nov 29 | Dec 15 |
| Hard (28°F) | Nov 23 | Dec 12 | Jan 6 |
| Severe (24°F) | Dec 2 | Dec 28 | Jan 24 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 4 | Nov 9 | Nov 13 | Nov 16 | Nov 19 | Nov 21 | Nov 24 | Nov 29 | Dec 3 |
| 32°F | Nov 12 | Nov 19 | Nov 22 | Nov 25 | Nov 29 | Dec 2 | Dec 5 | Dec 10 | Dec 15 |
| 28°F | Nov 23 | Nov 29 | Dec 4 | Dec 8 | Dec 12 | Dec 15 | Dec 21 | Dec 27 | Jan 6 |
| 24°F | Dec 2 | Dec 10 | Dec 16 | Dec 23 | Dec 28 | Jan 1 | Jan 5 | Jan 13 | Jan 24 |
| 20°F | Dec 19 | Dec 28 | Jan 1 | Jan 1 | Jan 4 | Jan 7 | Jan 9 | Jan 19 | Jan 27 |
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: Casa Grande Nm, Az, about 2.7 miles away@if(!empty($station['elevation_ft'])), at 1,419 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 Coolidge, AZ?
On average, the last spring frost (32°F) around Coolidge, AZ is about Feb 17. In cooler years it can run later, so for a safer bet many gardeners wait until Jan 22.
When is the first frost in the fall?
The first fall frost around Coolidge, AZ typically arrives about Nov 29. 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 17 on average, or Jan 22 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 284 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 85128 Planting calendar → Arizona frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026