Last spring frost
May 6
Frost Dates for Phoenix, OR
First fall frost
Oct 8
Growing season
154 days
Hardiness zone
8b
In an average year around Phoenix, OR, the last spring frost (32°F) is about May 6 and the first fall frost is about Oct 8, giving roughly a 154-day growing season. To be safe most years, wait until Apr 20 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 17 | May 29 | May 12 |
| Freeze (32°F) | May 27 | May 6 | Apr 20 |
| Hard (28°F) | May 4 | Apr 15 | Mar 27 |
| Severe (24°F) | Apr 10 | Mar 19 | Feb 21 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 17 | Jun 10 | Jun 6 | Jun 2 | May 29 | May 25 | May 21 | May 18 | May 12 |
| 32°F | May 27 | May 19 | May 14 | May 10 | May 6 | May 3 | Apr 30 | Apr 27 | Apr 20 |
| 28°F | May 4 | Apr 29 | Apr 24 | Apr 20 | Apr 15 | Apr 11 | Apr 6 | Apr 1 | Mar 27 |
| 24°F | Apr 10 | Apr 2 | Mar 29 | Mar 24 | Mar 19 | Mar 14 | Mar 8 | Mar 1 | Feb 21 |
| 20°F | Mar 10 | Mar 1 | Feb 25 | Feb 18 | Feb 12 | Feb 4 | Jan 26 | Jan 12 | Dec 28 |
| 16°F | Feb 16 | Jan 31 | Jan 22 | Jan 11 | Dec 31 | Dec 26 | Dec 20 | Dec 14 | 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) | Sep 6 | Sep 23 | Oct 9 |
| Freeze (32°F) | Sep 21 | Oct 8 | Oct 26 |
| Hard (28°F) | Oct 10 | Oct 26 | Nov 16 |
| Severe (24°F) | Oct 22 | Nov 12 | Dec 8 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 6 | Sep 12 | Sep 15 | Sep 19 | Sep 23 | Sep 26 | Sep 30 | Oct 4 | Oct 9 |
| 32°F | Sep 21 | Sep 28 | Oct 1 | Oct 5 | Oct 8 | Oct 12 | Oct 15 | Oct 20 | Oct 26 |
| 28°F | Oct 10 | Oct 16 | Oct 20 | Oct 23 | Oct 26 | Oct 30 | Nov 2 | Nov 7 | Nov 16 |
| 24°F | Oct 22 | Oct 29 | Nov 2 | Nov 7 | Nov 12 | Nov 18 | Nov 24 | Dec 1 | Dec 8 |
| 20°F | Nov 7 | Nov 15 | Nov 21 | Nov 29 | Dec 4 | Dec 10 | Dec 17 | Dec 27 | Jan 11 |
| 16°F | Nov 20 | Dec 1 | Dec 5 | Dec 11 | Dec 16 | Dec 21 | Dec 28 | Jan 5 | Jan 25 |
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: Ashland, Or, about 6.3 miles away@if(!empty($station['elevation_ft'])), at 1,729 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 Phoenix, OR?
On average, the last spring frost (32°F) around Phoenix, OR is about May 6. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 20.
When is the first frost in the fall?
The first fall frost around Phoenix, OR typically arrives about Oct 8. 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 6 on average, or Apr 20 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 154 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 97535 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026