Last spring frost
Mar 14
Frost Dates for Brownsville, OR
First fall frost
Nov 18
Growing season
248 days
Hardiness zone
8b
In an average year around Brownsville, OR, the last spring frost (32°F) is about Mar 14 and the first fall frost is about Nov 18, giving roughly a 248-day growing season. To be safe most years, wait until Feb 18 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 4 | Apr 15 | Mar 25 |
| Freeze (32°F) | Apr 14 | Mar 14 | Feb 18 |
| Hard (28°F) | Mar 8 | Feb 15 | Dec 26 |
| Severe (24°F) | Feb 20 | Jan 6 | Dec 5 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 4 | Apr 29 | Apr 24 | Apr 20 | Apr 15 | Apr 11 | Apr 5 | Mar 31 | Mar 25 |
| 32°F | Apr 14 | Apr 1 | Mar 25 | Mar 20 | Mar 14 | Mar 9 | Mar 2 | Feb 26 | Feb 18 |
| 28°F | Mar 8 | Mar 1 | Feb 25 | Feb 19 | Feb 15 | Feb 7 | Jan 27 | Jan 8 | Dec 26 |
| 24°F | Feb 20 | Feb 12 | Jan 31 | Jan 16 | Jan 6 | Dec 31 | Dec 24 | Dec 15 | Dec 5 |
| 20°F | Feb 14 | Jan 31 | Jan 10 | Dec 31 | Dec 28 | Dec 23 | Dec 18 | Dec 12 | Dec 4 |
| 16°F | Jan 7 | Dec 30 | Dec 28 | Dec 24 | Dec 22 | Dec 19 | Dec 14 | Dec 10 | 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 8 | Oct 28 | Nov 20 |
| Freeze (32°F) | Oct 27 | Nov 18 | Dec 15 |
| Hard (28°F) | Nov 8 | Dec 10 | Jan 16 |
| Severe (24°F) | Nov 22 | Dec 21 | Feb 8 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 8 | Oct 15 | Oct 20 | Oct 25 | Oct 28 | Nov 1 | Nov 5 | Nov 11 | Nov 20 |
| 32°F | Oct 27 | Nov 2 | Nov 7 | Nov 12 | Nov 18 | Nov 24 | Nov 30 | Dec 6 | Dec 15 |
| 28°F | Nov 8 | Nov 19 | Nov 28 | Dec 4 | Dec 10 | Dec 16 | Dec 22 | Jan 1 | Jan 16 |
| 24°F | Nov 22 | Dec 1 | Dec 8 | Dec 15 | Dec 21 | Dec 27 | Jan 2 | Jan 14 | Feb 8 |
| 20°F | Dec 1 | Dec 9 | Dec 13 | Dec 19 | Dec 23 | Dec 28 | Jan 2 | Jan 18 | Feb 9 |
| 16°F | Dec 3 | Dec 9 | Dec 13 | Dec 16 | Dec 20 | Dec 23 | Dec 26 | Dec 29 | Jan 2 |
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: Lebanon, Or, about 11.1 miles away@if(!empty($station['elevation_ft'])), at 330 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 Brownsville, OR?
On average, the last spring frost (32°F) around Brownsville, OR is about Mar 14. In cooler years it can run later, so for a safer bet many gardeners wait until Feb 18.
When is the first frost in the fall?
The first fall frost around Brownsville, OR typically arrives about Nov 18. 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 14 on average, or Feb 18 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 248 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 97327 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026