Last spring frost
May 27
Frost Dates for Rhododendron, OR
First fall frost
Oct 9
Growing season
134 days
Hardiness zone
7a
In an average year around Rhododendron, OR, the last spring frost (32°F) is about May 27 and the first fall frost is about Oct 9, giving roughly a 134-day growing season. To be safe most years, wait until May 4 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) | Jul 11 | Jun 21 | Jun 2 |
| Freeze (32°F) | Jun 14 | May 27 | May 4 |
| Hard (28°F) | May 22 | May 3 | Apr 16 |
| Severe (24°F) | May 4 | Apr 12 | Mar 16 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jul 11 | Jul 2 | Jun 30 | Jun 24 | Jun 21 | Jun 18 | Jun 14 | Jun 9 | Jun 2 |
| 32°F | Jun 14 | Jun 8 | Jun 2 | May 31 | May 27 | May 22 | May 18 | May 12 | May 4 |
| 28°F | May 22 | May 16 | May 12 | May 7 | May 3 | Apr 30 | Apr 28 | Apr 23 | Apr 16 |
| 24°F | May 4 | Apr 28 | Apr 22 | Apr 16 | Apr 12 | Apr 5 | Apr 1 | Mar 27 | Mar 16 |
| 20°F | Apr 12 | Apr 2 | Mar 27 | Mar 21 | Mar 14 | Mar 8 | Feb 28 | Feb 22 | Feb 15 |
| 16°F | Mar 17 | Mar 5 | Feb 28 | Feb 23 | Feb 16 | Feb 10 | Feb 2 | Jan 19 | Jan 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 27 | Sep 16 | Oct 6 |
| Freeze (32°F) | Sep 18 | Oct 9 | Oct 26 |
| Hard (28°F) | Oct 9 | Oct 28 | Nov 15 |
| Severe (24°F) | Oct 24 | Nov 13 | Dec 2 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Aug 27 | Sep 1 | Sep 6 | Sep 11 | Sep 16 | Sep 21 | Sep 27 | Oct 1 | Oct 6 |
| 32°F | Sep 18 | Sep 27 | Oct 1 | Oct 5 | Oct 9 | Oct 13 | Oct 16 | Oct 20 | Oct 26 |
| 28°F | Oct 9 | Oct 16 | Oct 20 | Oct 24 | Oct 28 | Nov 1 | Nov 4 | Nov 8 | Nov 15 |
| 24°F | Oct 24 | Nov 1 | Nov 5 | Nov 9 | Nov 13 | Nov 17 | Nov 22 | Nov 26 | Dec 2 |
| 20°F | Nov 5 | Nov 12 | Nov 17 | Nov 23 | Nov 29 | Dec 2 | Dec 7 | Dec 14 | Dec 22 |
| 16°F | Nov 17 | Nov 27 | Dec 2 | Dec 8 | Dec 15 | Dec 21 | Dec 29 | Jan 5 | Jan 27 |
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: Government Camp, Or, about 3.3 miles away@if(!empty($station['elevation_ft'])), at 3,980 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 Rhododendron, OR?
On average, the last spring frost (32°F) around Rhododendron, OR is about May 27. In cooler years it can run later, so for a safer bet many gardeners wait until May 4.
When is the first frost in the fall?
The first fall frost around Rhododendron, OR typically arrives about Oct 9. 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 27 on average, or May 4 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 134 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 97028 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026