Last spring frost
May 1
Frost Dates for Black Butte Ranch, OR
First fall frost
Oct 10
Growing season
159 days
Hardiness zone
7b
In an average year around Black Butte Ranch, OR, the last spring frost (32°F) is about May 1 and the first fall frost is about Oct 10, giving roughly a 159-day growing season. To be safe most years, wait until Apr 12 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 16 | May 25 | May 4 |
| Freeze (32°F) | May 19 | May 1 | Apr 12 |
| Hard (28°F) | Apr 30 | Apr 5 | Mar 7 |
| Severe (24°F) | Mar 26 | Feb 26 | Jan 15 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 16 | Jun 8 | Jun 2 | May 29 | May 25 | May 19 | May 14 | May 10 | May 4 |
| 32°F | May 19 | May 13 | May 8 | May 4 | May 1 | Apr 27 | Apr 24 | Apr 20 | Apr 12 |
| 28°F | Apr 30 | Apr 23 | Apr 17 | Apr 10 | Apr 5 | Mar 31 | Mar 27 | Mar 20 | Mar 7 |
| 24°F | Mar 26 | Mar 16 | Mar 8 | Mar 2 | Feb 26 | Feb 21 | Feb 12 | Feb 3 | Jan 15 |
| 20°F | Feb 25 | Feb 18 | Feb 9 | Jan 31 | Jan 23 | Jan 13 | Jan 5 | Dec 30 | Dec 13 |
| 16°F | Feb 15 | Feb 2 | Jan 19 | Jan 8 | Jan 2 | Dec 28 | Dec 19 | Dec 9 | Dec 3 |
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) | Aug 31 | Sep 21 | Oct 9 |
| Freeze (32°F) | Sep 20 | Oct 10 | Nov 2 |
| Hard (28°F) | Oct 7 | Nov 1 | Nov 29 |
| Severe (24°F) | Nov 1 | Nov 26 | Dec 24 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Aug 31 | Sep 7 | Sep 12 | Sep 16 | Sep 21 | Sep 26 | Oct 1 | Oct 4 | Oct 9 |
| 32°F | Sep 20 | Sep 28 | Oct 2 | Oct 6 | Oct 10 | Oct 16 | Oct 19 | Oct 24 | Nov 2 |
| 28°F | Oct 7 | Oct 18 | Oct 23 | Oct 29 | Nov 1 | Nov 6 | Nov 12 | Nov 19 | Nov 29 |
| 24°F | Nov 1 | Nov 9 | Nov 15 | Nov 22 | Nov 26 | Dec 1 | Dec 6 | Dec 15 | Dec 24 |
| 20°F | Nov 15 | Nov 26 | Dec 2 | Dec 7 | Dec 13 | Dec 21 | Dec 29 | Jan 8 | Jan 30 |
| 16°F | Nov 29 | Dec 5 | Dec 8 | Dec 15 | Dec 23 | Dec 30 | Jan 6 | Jan 19 | Feb 10 |
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: Mckenzie Rvr Rs, Or, about 12.1 miles away@if(!empty($station['elevation_ft'])), at 1,478 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 Black Butte Ranch, OR?
On average, the last spring frost (32°F) around Black Butte Ranch, OR is about May 1. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 12.
When is the first frost in the fall?
The first fall frost around Black Butte Ranch, OR 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 1 on average, or Apr 12 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 159 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 97413 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026