Last spring frost
Apr 18
Frost Dates for Lynden, WA
First fall frost
Oct 18
Growing season
185 days
Hardiness zone
8a
In an average year around Lynden, WA, the last spring frost (32°F) is about Apr 18 and the first fall frost is about Oct 18, giving roughly a 185-day growing season. To be safe most years, wait until Mar 27 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 22 | May 7 | Apr 23 |
| Freeze (32°F) | May 5 | Apr 18 | Mar 27 |
| Hard (28°F) | Apr 8 | Mar 18 | Feb 25 |
| Severe (24°F) | Mar 12 | Feb 21 | Jan 10 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 22 | May 17 | May 13 | May 10 | May 7 | May 4 | May 1 | Apr 28 | Apr 23 |
| 32°F | May 5 | May 1 | Apr 27 | Apr 22 | Apr 18 | Apr 14 | Apr 8 | Apr 3 | Mar 27 |
| 28°F | Apr 8 | Apr 1 | Mar 26 | Mar 22 | Mar 18 | Mar 14 | Mar 8 | Mar 3 | Feb 25 |
| 24°F | Mar 12 | Mar 6 | Mar 1 | Feb 26 | Feb 21 | Feb 15 | Feb 5 | Jan 27 | Jan 10 |
| 20°F | Feb 24 | Feb 17 | Feb 4 | Jan 30 | Jan 20 | Jan 11 | Jan 3 | Dec 23 | Dec 9 |
| 16°F | Feb 1 | Jan 27 | Jan 19 | Jan 12 | Jan 7 | Jan 1 | Dec 25 | Dec 14 | Dec 5 |
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 10 | Sep 29 | Oct 14 |
| Freeze (32°F) | Sep 28 | Oct 18 | Nov 8 |
| Hard (28°F) | Oct 20 | Nov 7 | Dec 4 |
| Severe (24°F) | Nov 6 | Dec 1 | Dec 30 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 10 | Sep 17 | Sep 22 | Sep 26 | Sep 29 | Oct 1 | Oct 4 | Oct 7 | Oct 14 |
| 32°F | Sep 28 | Oct 4 | Oct 8 | Oct 13 | Oct 18 | Oct 22 | Oct 28 | Nov 1 | Nov 8 |
| 28°F | Oct 20 | Oct 27 | Oct 31 | Nov 3 | Nov 7 | Nov 12 | Nov 18 | Nov 25 | Dec 4 |
| 24°F | Nov 6 | Nov 11 | Nov 18 | Nov 26 | Dec 1 | Dec 5 | Dec 12 | Dec 20 | Dec 30 |
| 20°F | Nov 20 | Nov 29 | Dec 3 | Dec 9 | Dec 16 | Dec 22 | Dec 30 | Jan 9 | Jan 25 |
| 16°F | Nov 29 | Dec 5 | Dec 11 | Dec 19 | Dec 27 | Jan 1 | Jan 7 | Jan 16 | Jan 26 |
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: Clearbrook, Wa, about 5.8 miles away@if(!empty($station['elevation_ft'])), at 64 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 Lynden, WA?
On average, the last spring frost (32°F) around Lynden, WA is about Apr 18. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 27.
When is the first frost in the fall?
The first fall frost around Lynden, WA typically arrives about Oct 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 Apr 18 on average, or Mar 27 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 185 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 98264 Planting calendar → Washington frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026