Last spring frost
Mar 28
Frost Dates for Dunes City, OR
First fall frost
Nov 22
Growing season
237 days
Hardiness zone
9a
In an average year around Dunes City, OR, the last spring frost (32°F) is about Mar 28 and the first fall frost is about Nov 22, giving roughly a 237-day growing season. To be safe most years, wait until Feb 23 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 20 | Apr 30 | Apr 7 |
| Freeze (32°F) | Apr 21 | Mar 28 | Feb 23 |
| Hard (28°F) | Mar 18 | Feb 18 | Dec 21 |
| Severe (24°F) | Feb 27 | Jan 3 | Dec 6 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 20 | May 13 | May 8 | May 3 | Apr 30 | Apr 27 | Apr 22 | Apr 15 | Apr 7 |
| 32°F | Apr 21 | Apr 11 | Apr 5 | Apr 1 | Mar 28 | Mar 22 | Mar 14 | Mar 3 | Feb 23 |
| 28°F | Mar 18 | Mar 8 | Feb 28 | Feb 24 | Feb 18 | Feb 9 | Jan 26 | Jan 7 | Dec 21 |
| 24°F | Feb 27 | Feb 15 | Jan 31 | Jan 14 | Jan 3 | Dec 29 | Dec 20 | Dec 13 | Dec 6 |
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 8 | Oct 31 | Nov 23 |
| Freeze (32°F) | Oct 28 | Nov 22 | Dec 20 |
| Hard (28°F) | Nov 13 | Dec 15 | Feb 12 |
| Severe (24°F) | Dec 1 | Dec 26 | Feb 21 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 8 | Oct 17 | Oct 23 | Oct 27 | Oct 31 | Nov 3 | Nov 8 | Nov 15 | Nov 23 |
| 32°F | Oct 28 | Nov 4 | Nov 11 | Nov 16 | Nov 22 | Nov 28 | Dec 2 | Dec 9 | Dec 20 |
| 28°F | Nov 13 | Nov 25 | Dec 2 | Dec 8 | Dec 15 | Dec 25 | Jan 2 | Jan 16 | Feb 12 |
| 24°F | Dec 1 | Dec 8 | Dec 12 | Dec 18 | Dec 26 | Jan 1 | Jan 10 | Jan 31 | Feb 21 |
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: Honeyman Sp, Or, about 4.5 miles away@if(!empty($station['elevation_ft'])), at 115 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 Dunes City, OR?
On average, the last spring frost (32°F) around Dunes City, OR is about Mar 28. In cooler years it can run later, so for a safer bet many gardeners wait until Feb 23.
When is the first frost in the fall?
The first fall frost around Dunes City, OR typically arrives about Nov 22. 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 28 on average, or Feb 23 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 237 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 97493 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026