Last spring frost
May 16
Frost Dates for Merlin, OR
First fall frost
Oct 30
Growing season
164 days
Hardiness zone
8b
In an average year around Merlin, OR, the last spring frost (32°F) is about May 16 and the first fall frost is about Oct 30, giving roughly a 164-day growing season. To be safe most years, wait until Apr 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) | Jun 25 | Jun 7 | May 16 |
| Freeze (32°F) | Jun 7 | May 16 | Apr 23 |
| Hard (28°F) | May 17 | Apr 23 | Mar 23 |
| Severe (24°F) | Apr 21 | Mar 18 | Jan 20 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 25 | Jun 19 | Jun 15 | Jun 10 | Jun 7 | Jun 3 | May 31 | May 25 | May 16 |
| 32°F | Jun 7 | Jun 1 | May 27 | May 22 | May 16 | May 10 | May 2 | Apr 29 | Apr 23 |
| 28°F | May 17 | May 8 | May 1 | Apr 26 | Apr 23 | Apr 17 | Apr 10 | Apr 1 | Mar 23 |
| 24°F | Apr 21 | Apr 8 | Mar 31 | Mar 26 | Mar 18 | Mar 9 | Feb 26 | Feb 13 | Jan 20 |
| 20°F | Mar 20 | Mar 2 | Feb 22 | Feb 11 | Jan 27 | Jan 15 | Jan 6 | Dec 30 | Dec 12 |
| 16°F | Feb 7 | Jan 26 | Jan 14 | Jan 9 | Jan 5 | Jan 1 | Dec 29 | Dec 15 | Dec 10 |
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 15 | Oct 9 | Nov 1 |
| Freeze (32°F) | Oct 8 | Oct 30 | Nov 17 |
| Hard (28°F) | Oct 28 | Nov 17 | Dec 10 |
| Severe (24°F) | Nov 14 | Dec 9 | Jan 24 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 15 | Sep 27 | Oct 1 | Oct 6 | Oct 9 | Oct 14 | Oct 17 | Oct 24 | Nov 1 |
| 32°F | Oct 8 | Oct 15 | Oct 21 | Oct 25 | Oct 30 | Nov 2 | Nov 5 | Nov 9 | Nov 17 |
| 28°F | Oct 28 | Nov 3 | Nov 7 | Nov 11 | Nov 17 | Nov 22 | Nov 28 | Dec 2 | Dec 10 |
| 24°F | Nov 14 | Nov 23 | Nov 30 | Dec 4 | Dec 9 | Dec 15 | Dec 23 | Jan 3 | Jan 24 |
| 20°F | Dec 1 | Dec 8 | Dec 15 | Dec 25 | Jan 1 | Jan 5 | Jan 17 | Feb 1 | Feb 26 |
| 16°F | Dec 7 | Dec 12 | Dec 19 | Dec 30 | Jan 2 | Jan 5 | Jan 11 | Jan 23 | Jan 31 |
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: Sexton Summit, Or, about 4.7 miles away@if(!empty($station['elevation_ft'])), at 3,832 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 Merlin, OR?
On average, the last spring frost (32°F) around Merlin, OR is about May 16. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 23.
When is the first frost in the fall?
The first fall frost around Merlin, OR typically arrives about Oct 30. 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 16 on average, or Apr 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 164 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 97526 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026