Last spring frost
May 11
Frost Dates for Snowflake, AZ
First fall frost
Oct 10
Growing season
149 days
Hardiness zone
7a
In an average year around Snowflake, AZ, the last spring frost (32°F) is about May 11 and the first fall frost is about Oct 10, giving roughly a 149-day growing season. To be safe most years, wait until Apr 27 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) | Jun 12 | May 26 | May 10 |
| Freeze (32°F) | May 31 | May 11 | Apr 27 |
| Hard (28°F) | May 15 | Apr 29 | Apr 12 |
| Severe (24°F) | May 3 | Apr 11 | Mar 22 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 12 | Jun 6 | Jun 3 | May 31 | May 26 | May 22 | May 18 | May 14 | May 10 |
| 32°F | May 31 | May 22 | May 17 | May 14 | May 11 | May 8 | May 5 | May 2 | Apr 27 |
| 28°F | May 15 | May 10 | May 6 | May 2 | Apr 29 | Apr 26 | Apr 22 | Apr 19 | Apr 12 |
| 24°F | May 3 | Apr 26 | Apr 20 | Apr 15 | Apr 11 | Apr 7 | Apr 3 | Mar 30 | Mar 22 |
| 20°F | Apr 14 | Apr 6 | Apr 2 | Mar 28 | Mar 23 | Mar 18 | Mar 14 | Mar 10 | Mar 5 |
| 16°F | Mar 26 | Mar 16 | Mar 11 | Mar 7 | Mar 3 | Mar 1 | Feb 25 | Feb 19 | Feb 8 |
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) | Sep 20 | Oct 2 | Oct 13 |
| Freeze (32°F) | Sep 28 | Oct 10 | Oct 22 |
| Hard (28°F) | Oct 6 | Oct 20 | Nov 2 |
| Severe (24°F) | Oct 15 | Oct 30 | Nov 12 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 20 | Sep 25 | Sep 27 | Oct 1 | Oct 2 | Oct 4 | Oct 5 | Oct 8 | Oct 13 |
| 32°F | Sep 28 | Oct 2 | Oct 5 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 18 | Oct 22 |
| 28°F | Oct 6 | Oct 10 | Oct 14 | Oct 18 | Oct 20 | Oct 23 | Oct 26 | Oct 29 | Nov 2 |
| 24°F | Oct 15 | Oct 20 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 12 |
| 20°F | Oct 25 | Oct 31 | Nov 3 | Nov 6 | Nov 9 | Nov 11 | Nov 15 | Nov 18 | Nov 23 |
| 16°F | Nov 5 | Nov 10 | Nov 14 | Nov 18 | Nov 20 | Nov 23 | Nov 26 | Nov 30 | Dec 4 |
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: Snowflake, Az, about 5.8 miles away@if(!empty($station['elevation_ft'])), at 5,642 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 Snowflake, AZ?
On average, the last spring frost (32°F) around Snowflake, AZ is about May 11. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 27.
When is the first frost in the fall?
The first fall frost around Snowflake, AZ typically arrives about Oct 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 May 11 on average, or Apr 27 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 149 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 85937 Planting calendar → Arizona frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026