Last spring frost
Feb 21
Frost Dates for Coos Bay, OR
First fall frost
Dec 9
Growing season
294 days
Hardiness zone
9a
In an average year around Coos Bay, OR, the last spring frost (32°F) is about Feb 21 and the first fall frost is about Dec 9, giving roughly a 294-day growing season. To be safe most years, wait until Dec 31 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 1 | Apr 2 | Mar 1 |
| Freeze (32°F) | Mar 25 | Feb 21 | Dec 31 |
| Hard (28°F) | Feb 22 | Jan 4 | Dec 3 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 1 | Apr 23 | Apr 16 | Apr 8 | Apr 2 | Mar 29 | Mar 24 | Mar 15 | Mar 1 |
| 32°F | Mar 25 | Mar 14 | Mar 5 | Feb 26 | Feb 21 | Feb 13 | Feb 6 | Jan 26 | Dec 31 |
| 28°F | Feb 22 | Feb 14 | Feb 1 | Jan 18 | Jan 4 | Dec 29 | Dec 22 | Dec 13 | Dec 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) | Oct 24 | Nov 15 | Dec 11 |
| Freeze (32°F) | Nov 12 | Dec 9 | Jan 28 |
| Hard (28°F) | Nov 25 | Dec 22 | Feb 15 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 24 | Oct 31 | Nov 5 | Nov 10 | Nov 15 | Nov 19 | Nov 25 | Dec 1 | Dec 11 |
| 32°F | Nov 12 | Nov 21 | Nov 27 | Dec 2 | Dec 9 | Dec 16 | Dec 25 | Jan 4 | Jan 28 |
| 28°F | Nov 25 | Dec 5 | Dec 10 | Dec 15 | Dec 22 | Dec 30 | Jan 10 | Jan 28 | Feb 15 |
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: North Bend Rgnl Ap, Or, about 8.3 miles away@if(!empty($station['elevation_ft'])), at 17 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 Coos Bay, OR?
On average, the last spring frost (32°F) around Coos Bay, OR is about Feb 21. In cooler years it can run later, so for a safer bet many gardeners wait until Dec 31.
When is the first frost in the fall?
The first fall frost around Coos Bay, OR typically arrives about Dec 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 Feb 21 on average, or Dec 31 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 294 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 97420 Planting calendar → Oregon frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026