Last spring frost
Apr 22
Frost Dates for Rochester, WA
First fall frost
Oct 27
Growing season
188 days
Hardiness zone
8b
In an average year around Rochester, WA, the last spring frost (32°F) is about Apr 22 and the first fall frost is about Oct 27, giving roughly a 188-day growing season. To be safe most years, wait until Mar 30 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 24 | May 7 | Apr 24 |
| Freeze (32°F) | May 10 | Apr 22 | Mar 30 |
| Hard (28°F) | Apr 17 | Mar 23 | Feb 24 |
| Severe (24°F) | Mar 17 | Feb 20 | Jan 2 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 24 | May 18 | May 14 | May 11 | May 7 | May 4 | May 1 | Apr 28 | Apr 24 |
| 32°F | May 10 | May 4 | Apr 30 | Apr 26 | Apr 22 | Apr 18 | Apr 12 | Apr 5 | Mar 30 |
| 28°F | Apr 17 | Apr 6 | Mar 31 | Mar 27 | Mar 23 | Mar 18 | Mar 12 | Mar 4 | Feb 24 |
| 24°F | Mar 17 | Mar 8 | Mar 2 | Feb 26 | Feb 20 | Feb 14 | Feb 3 | Jan 21 | Jan 2 |
| 20°F | Mar 4 | Feb 25 | Feb 17 | Feb 8 | Jan 27 | Jan 13 | Jan 2 | Dec 22 | Dec 10 |
| 16°F | Feb 25 | Feb 15 | Feb 1 | Jan 12 | Jan 1 | Dec 24 | Dec 16 | Dec 9 | Dec 2 |
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) | Sep 22 | Oct 8 | Oct 26 |
| Freeze (32°F) | Oct 7 | Oct 27 | Nov 17 |
| Hard (28°F) | Oct 21 | Nov 13 | Dec 7 |
| Severe (24°F) | Nov 6 | Nov 30 | Jan 1 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 22 | Sep 29 | Oct 1 | Oct 5 | Oct 8 | Oct 13 | Oct 17 | Oct 21 | Oct 26 |
| 32°F | Oct 7 | Oct 15 | Oct 19 | Oct 23 | Oct 27 | Oct 31 | Nov 3 | Nov 8 | Nov 17 |
| 28°F | Oct 21 | Oct 30 | Nov 4 | Nov 8 | Nov 13 | Nov 17 | Nov 22 | Nov 28 | Dec 7 |
| 24°F | Nov 6 | Nov 13 | Nov 19 | Nov 25 | Nov 30 | Dec 6 | Dec 12 | Dec 21 | Jan 1 |
| 20°F | Nov 17 | Nov 27 | Dec 3 | Dec 9 | Dec 16 | Dec 23 | Jan 1 | Jan 12 | Feb 8 |
| 16°F | Nov 27 | Dec 3 | Dec 7 | Dec 13 | Dec 22 | Dec 31 | Jan 10 | Feb 2 | Feb 19 |
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: Centralia, Wa, about 9.4 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 Rochester, WA?
On average, the last spring frost (32°F) around Rochester, WA is about Apr 22. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 30.
When is the first frost in the fall?
The first fall frost around Rochester, WA typically arrives about Oct 27. 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 22 on average, or Mar 30 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 188 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 98579 Planting calendar → Washington frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026