Frost dates for 98278 — Oak Harbor, WA
Last spring frostMar 13median date
First fall frostNov 14median date
Growing season246 daysfrost-free
Hardiness zone8bZone 8b
How Oak Harbor compares
- In 8 years out of 10, the last spring frost in Oak Harbor falls between February 20 and April 1, a 40-day window. The first fall frost falls between October 26 and December 5.
- The median last frost is 39 days earlier than the Washington median of Apr 21.
- Its 246-day growing season is longer than 89% of the 491 Washington places with a regular frost season (state median 182 days).
- The last frost is typical for zone 8b, where the median is Mar 16.
- The weather station records an average of 40 nights a year at or below 32°F.
- Compared with Marysville, WA, 46 km away, the last frost here is 11 days earlier than there and the growing season is 23 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | February 20 |
| 50% (median) | March 13 |
| 10% (safe for tender plants) | April 1 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 26 |
| 50% (median) | November 14 |
| 90% (late) | December 5 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Oak Harbor, WA
Frost dates for 98278 — Oak Harbor, WA — last frost Mar 13, first frost Nov 14, zone 8b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Dec 19 to Jan 2Start indoors: Dec 19 to Jan 2Transplant outside: Feb 13 to Feb 27
Start indoors: Jan 2 to Jan 16Transplant outside: Mar 27 to Apr 10
Start indoors: Jan 2 to Jan 16Transplant outside: Mar 27 to Apr 10
Start indoors: Jan 16 to Jan 30Transplant outside: Mar 20 to Apr 3
Start indoors: Jan 16 to Jan 30Transplant outside: Feb 20 to Mar 6Sow outdoors: Feb 13 to Mar 20Plant for fall: Sep 19 to Oct 17
Start indoors: Jan 16 to Jan 30Transplant outside: Feb 13 to Feb 27Sow outdoors: Feb 13 to Feb 27Plant for fall: Sep 5 to Sep 26
Start indoors: Jan 16 to Jan 30Transplant outside: Feb 27 to Mar 13Plant for fall: Aug 8 to Aug 29
Start indoors: Jan 16 to Jan 30Transplant outside: Feb 20 to Mar 6Plant for fall: Aug 8 to Aug 29
Start indoors: Jan 16 to Jan 30Transplant outside: Feb 27 to Mar 13Plant for fall: Aug 8 to Aug 29
Start indoors: Jan 30 to Feb 13Transplant outside: Apr 3 to Apr 17Sow outdoors: Apr 3 to Apr 17
Start indoors: Jan 30 to Feb 13Transplant outside: Mar 20 to Apr 3
Sow outdoors: Jan 30 to Feb 20Plant for fall: Aug 22 to Sep 12
Sow outdoors: Jan 30 to Feb 20Plant for fall: Sep 19 to Oct 10
Sow outdoors: Feb 6 to Mar 20Plant for fall: Oct 3 to Oct 24
Start indoors: Feb 13 to Feb 20Transplant outside: Mar 27 to Apr 3Sow outdoors: Mar 20 to Apr 3Plant for fall: Aug 29 to Sep 12
Start indoors: Feb 13 to Feb 20Sow outdoors: Mar 20 to Apr 3Plant for fall: Sep 5 to Sep 19
Start indoors: Feb 13 to Feb 20Sow outdoors: Mar 20 to Apr 3
Start indoors: Feb 13 to Feb 20Transplant outside: Mar 27 to Apr 10
Sow outdoors: Feb 20 to Mar 20Plant for fall: Aug 22 to Sep 5
Sow outdoors: Feb 20 to Mar 20Plant for fall: Sep 5 to Sep 19
Sow outdoors: Feb 20 to Mar 13
Sow outdoors: Feb 27 to Mar 27Plant for fall: Sep 5 to Sep 19
Sow outdoors: Feb 27 to Mar 20Plant for fall: Sep 19 to Oct 10
Sow outdoors: Mar 20 to Apr 10Plant for fall: Aug 29 to Sep 12
Sow outdoors: Mar 20 to Apr 3
Transplant outside: Mar 27 to Apr 17
Plant for fall: Oct 31 to Dec 5
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Oak Harbor, WA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Dec 19 – Jan 2 | Feb 13 – Feb 27 | — | — |
| Peppers | Jan 2 – Jan 16 | Mar 27 – Apr 10 | — | — |
| Eggplant | Jan 2 – Jan 16 | Mar 27 – Apr 10 | — | — |
| Tomatoes | Jan 16 – Jan 30 | Mar 20 – Apr 3 | — | — |
| Lettuce | Jan 16 – Jan 30 | Feb 20 – Mar 6 | Feb 13 – Mar 20 | Sep 19 – Oct 17 |
| Kale | Jan 16 – Jan 30 | Feb 13 – Feb 27 | Feb 13 – Feb 27 | Sep 5 – Sep 26 |
| Broccoli | Jan 16 – Jan 30 | Feb 27 – Mar 13 | — | Aug 8 – Aug 29 |
| Cabbage | Jan 16 – Jan 30 | Feb 20 – Mar 6 | — | Aug 8 – Aug 29 |
| Cauliflower | Jan 16 – Jan 30 | Feb 27 – Mar 13 | — | Aug 8 – Aug 29 |
| Okra | Jan 30 – Feb 13 | Apr 3 – Apr 17 | Apr 3 – Apr 17 | — |
| Basil | Jan 30 – Feb 13 | Mar 20 – Apr 3 | — | — |
| Peas | — | — | Jan 30 – Feb 20 | Aug 22 – Sep 12 |
| Spinach | — | — | Jan 30 – Feb 20 | Sep 19 – Oct 10 |
| Radishes | — | — | Feb 6 – Mar 20 | Oct 3 – Oct 24 |
| Cucumbers | Feb 13 – Feb 20 | Mar 27 – Apr 3 | Mar 20 – Apr 3 | Aug 29 – Sep 12 |
| Zucchini & Summer Squash | Feb 13 – Feb 20 | — | Mar 20 – Apr 3 | Sep 5 – Sep 19 |
| Winter Squash & Pumpkins | Feb 13 – Feb 20 | — | Mar 20 – Apr 3 | — |
| Melons & Watermelon | Feb 13 – Feb 20 | Mar 27 – Apr 10 | — | — |
| Carrots | — | — | Feb 20 – Mar 20 | Aug 22 – Sep 5 |
| Beets | — | — | Feb 20 – Mar 20 | Sep 5 – Sep 19 |
| Potatoes | — | — | Feb 20 – Mar 13 | — |
| Swiss Chard | — | — | Feb 27 – Mar 27 | Sep 5 – Sep 19 |
| Cilantro | — | — | Feb 27 – Mar 20 | Sep 19 – Oct 10 |
| Green Beans | — | — | Mar 20 – Apr 10 | Aug 29 – Sep 12 |
| Sweet Corn | — | — | Mar 20 – Apr 3 | — |
| Sweet Potatoes | — | Mar 27 – Apr 17 | — | — |
| Garlic | — | — | — | Oct 31 – Dec 5 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Whidbey Island Nas, WA weather station, about 1 km away (elevation 46 ft (14 m)).
ZIP codes in Oak Harbor: 98277 98278
Frost dates near Oak Harbor
- La Conner Mar 24 · Nov 3
- Coupeville Mar 17 · Nov 11
- Anacortes Mar 8 · Nov 20
- Camano Island Mar 17 · Nov 11
- Lopez Island Mar 26 · Nov 10
- Conway Mar 24 · Nov 3
- Stanwood Apr 22 · Oct 19
- Blakely Island Feb 26 · Nov 29
Frequently asked questions
When is the last frost in Oak Harbor, WA?
The median last spring frost in Oak Harbor, WA is March 13. There is still about a 10% chance of frost after April 1, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Oak Harbor, WA?
The median first fall frost is November 14, with about a 10% chance of frost before October 26.
How long is the growing season in Oak Harbor, WA?
About 246 days between the median last spring frost and first fall frost.
What planting zone is Oak Harbor, WA?
Oak Harbor, WA is in USDA hardiness zone 8b.