Last spring frost
Feb 11
Frost Dates for Beaverton, OR
First fall frost
Dec 5
Growing season
303 days
Hardiness zone
8b
In an average year around Beaverton, OR, the last spring frost (32°F) is about Feb 11 and the first fall frost is about Dec 5, giving roughly a 303-day growing season. To be safe most years, wait until Dec 26 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) | Apr 15 | Mar 23 | Feb 25 |
| Freeze (32°F) | Mar 5 | Feb 11 | Dec 26 |
| Hard (28°F) | Feb 16 | Jan 6 | Dec 2 |
| Severe (24°F) | Feb 11 | Jan 1 | Dec 4 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 15 | Apr 6 | Mar 31 | Mar 26 | Mar 23 | Mar 18 | Mar 11 | Mar 4 | Feb 25 |
| 32°F | Mar 5 | Feb 27 | Feb 22 | Feb 17 | Feb 11 | Feb 3 | Jan 25 | Jan 9 | Dec 26 |
| 28°F | Feb 16 | Feb 6 | Jan 28 | Jan 16 | Jan 6 | Jan 1 | Dec 22 | Dec 12 | Dec 2 |
| 24°F | Feb 11 | Feb 1 | Jan 23 | Jan 12 | Jan 1 | Dec 30 | Dec 19 | Dec 13 | Dec 4 |
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 26 | Nov 13 | Dec 4 |
| Freeze (32°F) | Nov 11 | Dec 5 | Jan 12 |
| Hard (28°F) | Nov 24 | Dec 21 | Feb 5 |
| Severe (24°F) | Dec 2 | Dec 30 | Feb 5 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 26 | Nov 1 | Nov 5 | Nov 10 | Nov 13 | Nov 17 | Nov 22 | Nov 28 | Dec 4 |
| 32°F | Nov 11 | Nov 18 | Nov 24 | Nov 30 | Dec 5 | Dec 10 | Dec 18 | Dec 29 | Jan 12 |
| 28°F | Nov 24 | Dec 1 | Dec 7 | Dec 12 | Dec 21 | Dec 31 | Jan 6 | Jan 19 | Feb 5 |
| 24°F | Dec 2 | Dec 8 | Dec 13 | Dec 21 | Dec 30 | Jan 1 | Jan 16 | Jan 30 | Feb 5 |
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: Nature Park-Beaverton, Or, about 2.1 miles away@if(!empty($station['elevation_ft'])), at 185 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 Beaverton, OR?
On average, the last spring frost (32°F) around Beaverton, OR is about Feb 11. In cooler years it can run later, so for a safer bet many gardeners wait until Dec 26.
When is the first frost in the fall?
The first fall frost around Beaverton, OR typically arrives about Dec 5. 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 Feb 11 on average, or Dec 26 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 303 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 97006 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026