Last spring frost
Apr 1
Frost Dates for Beaverton, OR
First fall frost
Nov 6
Growing season
222 days
Hardiness zone
9a
In an average year around Beaverton, OR, the last spring frost (32°F) is about Apr 1 and the first fall frost is about Nov 6, giving roughly a 222-day growing season. To be safe most years, wait until Mar 5 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 16 | Apr 28 | Apr 11 |
| Freeze (32°F) | Apr 26 | Apr 1 | Mar 5 |
| Hard (28°F) | Mar 26 | Feb 26 | Jan 23 |
| Severe (24°F) | Feb 28 | Feb 1 | Dec 15 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 16 | May 8 | May 4 | Apr 30 | Apr 28 | Apr 25 | Apr 22 | Apr 17 | Apr 11 |
| 32°F | Apr 26 | Apr 18 | Apr 11 | Apr 6 | Apr 1 | Mar 28 | Mar 22 | Mar 15 | Mar 5 |
| 28°F | Mar 26 | Mar 16 | Mar 8 | Mar 2 | Feb 26 | Feb 22 | Feb 17 | Feb 9 | Jan 23 |
| 24°F | Feb 28 | Feb 22 | Feb 16 | Feb 10 | Feb 1 | Jan 24 | Jan 12 | Dec 31 | Dec 15 |
| 20°F | Feb 19 | Feb 13 | Feb 4 | Jan 25 | Jan 13 | Jan 2 | Dec 24 | Dec 15 | Dec 5 |
| 16°F | Feb 22 | Feb 14 | Feb 6 | Jan 25 | Jan 1 | Dec 27 | Dec 22 | Dec 16 | 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) | Oct 4 | Oct 21 | Nov 7 |
| Freeze (32°F) | Oct 19 | Nov 6 | Dec 1 |
| Hard (28°F) | Nov 6 | Nov 30 | Dec 27 |
| Severe (24°F) | Nov 18 | Dec 19 | Feb 3 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 4 | Oct 10 | Oct 14 | Oct 18 | Oct 21 | Oct 24 | Oct 27 | Oct 31 | Nov 7 |
| 32°F | Oct 19 | Oct 25 | Oct 29 | Nov 1 | Nov 6 | Nov 11 | Nov 17 | Nov 22 | Dec 1 |
| 28°F | Nov 6 | Nov 13 | Nov 20 | Nov 25 | Nov 30 | Dec 4 | Dec 9 | Dec 17 | Dec 27 |
| 24°F | Nov 18 | Nov 28 | Dec 5 | Dec 11 | Dec 19 | Dec 28 | Jan 5 | Jan 19 | Feb 3 |
| 20°F | Dec 1 | Dec 6 | Dec 13 | Dec 22 | Dec 30 | Jan 9 | Jan 20 | Feb 4 | Feb 14 |
| 16°F | Dec 5 | Dec 12 | Dec 19 | Dec 23 | Dec 30 | Jan 12 | Feb 4 | Feb 13 | Feb 20 |
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: Beaverton 2 Ssw, Or, about 1 miles away@if(!empty($station['elevation_ft'])), at 270 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 Apr 1. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 5.
When is the first frost in the fall?
The first fall frost around Beaverton, OR typically arrives about Nov 6. 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 Apr 1 on average, or Mar 5 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 222 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 97008 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026