Last spring frost
Mar 25
Frost Dates for Weston, OR
First fall frost
Oct 29
Growing season
218 days
Hardiness zone
7a
In an average year around Weston, OR, the last spring frost (32°F) is about Mar 25 and the first fall frost is about Oct 29, giving roughly a 218-day growing season. To be safe most years, wait until Mar 6 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 8 | Apr 19 | Mar 29 |
| Freeze (32°F) | Apr 16 | Mar 25 | Mar 6 |
| Hard (28°F) | Mar 28 | Mar 5 | Feb 17 |
| Severe (24°F) | Mar 11 | Feb 21 | Jan 22 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 8 | May 2 | Apr 28 | Apr 23 | Apr 19 | Apr 13 | Apr 8 | Apr 4 | Mar 29 |
| 32°F | Apr 16 | Apr 8 | Apr 3 | Mar 30 | Mar 25 | Mar 21 | Mar 16 | Mar 11 | Mar 6 |
| 28°F | Mar 28 | Mar 21 | Mar 14 | Mar 9 | Mar 5 | Mar 3 | Feb 28 | Feb 24 | Feb 17 |
| 24°F | Mar 11 | Mar 4 | Feb 28 | Feb 25 | Feb 21 | Feb 17 | Feb 11 | Feb 3 | Jan 22 |
| 20°F | Mar 1 | Feb 24 | Feb 19 | Feb 13 | Feb 7 | Jan 31 | Jan 22 | Jan 13 | Jan 1 |
| 16°F | Feb 26 | Feb 16 | Feb 8 | Feb 2 | Jan 27 | Jan 18 | Jan 10 | Jan 2 | Dec 18 |
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 2 | Oct 17 | Nov 2 |
| Freeze (32°F) | Oct 12 | Oct 29 | Nov 16 |
| Hard (28°F) | Oct 24 | Nov 11 | Dec 1 |
| Severe (24°F) | Nov 2 | Nov 24 | Dec 17 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 2 | Oct 7 | Oct 12 | Oct 15 | Oct 17 | Oct 20 | Oct 23 | Oct 27 | Nov 2 |
| 32°F | Oct 12 | Oct 18 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 5 | Nov 10 | Nov 16 |
| 28°F | Oct 24 | Oct 31 | Nov 3 | Nov 7 | Nov 11 | Nov 15 | Nov 20 | Nov 24 | Dec 1 |
| 24°F | Nov 2 | Nov 8 | Nov 13 | Nov 20 | Nov 24 | Nov 28 | Dec 3 | Dec 9 | Dec 17 |
| 20°F | Nov 9 | Nov 18 | Nov 25 | Nov 29 | Dec 5 | Dec 10 | Dec 18 | Dec 26 | Jan 7 |
| 16°F | Nov 15 | Nov 26 | Dec 2 | Dec 9 | Dec 16 | Dec 23 | Jan 1 | Jan 10 | Jan 29 |
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: Milton Freewater, Or, about 11.7 miles away@if(!empty($station['elevation_ft'])), at 970 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 Weston, OR?
On average, the last spring frost (32°F) around Weston, OR is about Mar 25. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 6.
When is the first frost in the fall?
The first fall frost around Weston, OR typically arrives about Oct 29. 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 Mar 25 on average, or Mar 6 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 218 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 97886 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026