Last spring frost
Mar 30
Frost Dates for Powers, OR
First fall frost
Nov 17
Growing season
233 days
Hardiness zone
9a
In an average year around Powers, OR, the last spring frost (32°F) is about Mar 30 and the first fall frost is about Nov 17, giving roughly a 233-day growing season. To be safe most years, wait until Feb 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) | May 25 | May 6 | Apr 14 |
| Freeze (32°F) | May 2 | Mar 30 | Feb 20 |
| Hard (28°F) | Mar 18 | Feb 1 | Dec 15 |
| Severe (24°F) | Jan 26 | Dec 29 | Dec 2 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 25 | May 19 | May 15 | May 10 | May 6 | May 3 | Apr 30 | Apr 24 | Apr 14 |
| 32°F | May 2 | Apr 20 | Apr 12 | Apr 4 | Mar 30 | Mar 23 | Mar 13 | Mar 2 | Feb 20 |
| 28°F | Mar 18 | Mar 2 | Feb 23 | Feb 12 | Feb 1 | Jan 19 | Jan 6 | Dec 29 | Dec 15 |
| 24°F | Jan 26 | Jan 13 | Jan 5 | Jan 1 | Dec 29 | Dec 24 | Dec 19 | Dec 10 | Dec 2 |
| 20°F | Jan 5 | Dec 31 | Dec 29 | Dec 24 | Dec 21 | Dec 18 | Dec 15 | Dec 9 | Dec 2 |
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 1 | Oct 26 | Nov 16 |
| Freeze (32°F) | Oct 20 | Nov 17 | Dec 15 |
| Hard (28°F) | Nov 8 | Dec 10 | Jan 26 |
| Severe (24°F) | Nov 29 | Dec 19 | Jan 17 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 1 | Oct 9 | Oct 15 | Oct 21 | Oct 26 | Oct 30 | Nov 4 | Nov 9 | Nov 16 |
| 32°F | Oct 20 | Oct 29 | Nov 5 | Nov 11 | Nov 17 | Nov 24 | Nov 29 | Dec 5 | Dec 15 |
| 28°F | Nov 8 | Nov 20 | Nov 28 | Dec 2 | Dec 10 | Dec 17 | Dec 25 | Jan 2 | Jan 26 |
| 24°F | Nov 29 | Dec 1 | Dec 6 | Dec 14 | Dec 19 | Dec 24 | Dec 29 | Jan 1 | Jan 17 |
| 20°F | Dec 2 | Dec 7 | Dec 13 | Dec 16 | Dec 19 | Dec 24 | Dec 27 | Dec 31 | Jan 2 |
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: Illahe, Or, about 2 miles away@if(!empty($station['elevation_ft'])), at 348 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 Powers, OR?
On average, the last spring frost (32°F) around Powers, OR is about Mar 30. In cooler years it can run later, so for a safer bet many gardeners wait until Feb 20.
When is the first frost in the fall?
The first fall frost around Powers, OR typically arrives about Nov 17. 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 Mar 30 on average, or Feb 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 233 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 97406 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026