Last spring frost
Mar 11
Frost Dates for Anderson Island, WA
First fall frost
Nov 21
Growing season
254 days
Hardiness zone
8b
In an average year around Anderson Island, WA, the last spring frost (32°F) is about Mar 11 and the first fall frost is about Nov 21, giving roughly a 254-day growing season. To be safe most years, wait until Feb 15 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 2 | Apr 11 | Mar 26 |
| Freeze (32°F) | Apr 2 | Mar 11 | Feb 15 |
| Hard (28°F) | Mar 8 | Feb 13 | Jan 1 |
| Severe (24°F) | Feb 19 | Jan 11 | Dec 2 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 2 | Apr 25 | Apr 20 | Apr 15 | Apr 11 | Apr 8 | Apr 4 | Apr 1 | Mar 26 |
| 32°F | Apr 2 | Mar 27 | Mar 21 | Mar 16 | Mar 11 | Mar 5 | Mar 1 | Feb 23 | Feb 15 |
| 28°F | Mar 8 | Feb 28 | Feb 23 | Feb 18 | Feb 13 | Feb 6 | Jan 29 | Jan 13 | Jan 1 |
| 24°F | Feb 19 | Feb 10 | Feb 1 | Jan 22 | Jan 11 | Jan 2 | Dec 21 | Dec 10 | Dec 2 |
| 20°F | Feb 10 | Jan 29 | Jan 14 | Jan 4 | Jan 1 | Dec 23 | Dec 13 | Dec 6 | Dec 1 |
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 21 | Nov 4 | Nov 19 |
| Freeze (32°F) | Nov 3 | Nov 21 | Dec 10 |
| Hard (28°F) | Nov 18 | Dec 11 | Jan 19 |
| Severe (24°F) | Nov 26 | Dec 19 | Feb 5 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 21 | Oct 26 | Oct 29 | Oct 31 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 19 |
| 32°F | Nov 3 | Nov 9 | Nov 13 | Nov 16 | Nov 21 | Nov 24 | Nov 28 | Dec 2 | Dec 10 |
| 28°F | Nov 18 | Nov 25 | Dec 1 | Dec 5 | Dec 11 | Dec 17 | Dec 26 | Jan 1 | Jan 19 |
| 24°F | Nov 26 | Dec 1 | Dec 6 | Dec 12 | Dec 19 | Dec 29 | Jan 5 | Jan 20 | Feb 5 |
| 20°F | Nov 29 | Dec 4 | Dec 8 | Dec 15 | Dec 24 | Jan 1 | Jan 4 | Jan 17 | Feb 3 |
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: Tacoma Narrows Ap, Wa, about 6.5 miles away@if(!empty($station['elevation_ft'])), at 292 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 Anderson Island, WA?
On average, the last spring frost (32°F) around Anderson Island, WA is about Mar 11. In cooler years it can run later, so for a safer bet many gardeners wait until Feb 15.
When is the first frost in the fall?
The first fall frost around Anderson Island, WA typically arrives about Nov 21. 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 11 on average, or Feb 15 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 254 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 98388 Planting calendar → Washington frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026