Frost dates for 98274 — Mount Vernon, WA
Last spring frostMar 27median date
First fall frostNov 6median date
Growing season224 daysfrost-free
Hardiness zone8bZone 8b
How Mount Vernon compares
- In 8 years out of 10, the last spring frost in Mount Vernon falls between March 8 and April 17, a 40-day window. The first fall frost falls between October 15 and November 28.
- The median last frost is 25 days earlier than the Washington median of Apr 21.
- Its 224-day growing season is longer than 78% of the 491 Washington places with a regular frost season (state median 182 days).
- The last frost is 11 days later than the zone 8b median of Mar 16. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 8b chart.
- The weather station records an average of 46 nights a year at or below 32°F.
- Compared with Marysville, WA, 31 km away, the last frost here is 3 days later than there and the growing season is 1 day longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 8 |
| 50% (median) | March 27 |
| 10% (safe for tender plants) | April 17 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 15 |
| 50% (median) | November 6 |
| 90% (late) | November 28 |
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 Mount Vernon, WA
Frost dates for 98274 — Mount Vernon, WA — last frost Mar 27, first frost Nov 6, zone 8b. whenisthelastfrost.com
Crop
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Start indoors: Jan 2 to Jan 16Transplant outside: Feb 27 to Mar 13
Start indoors: Jan 16 to Jan 30Transplant outside: Apr 10 to Apr 24
Start indoors: Jan 16 to Jan 30Transplant outside: Apr 10 to Apr 24
Start indoors: Jan 30 to Feb 13Transplant outside: Apr 3 to Apr 17
Start indoors: Jan 30 to Feb 13Transplant outside: Mar 6 to Mar 20Sow outdoors: Feb 27 to Apr 3Plant for fall: Sep 11 to Oct 9
Start indoors: Jan 30 to Feb 13Transplant outside: Feb 27 to Mar 13Sow outdoors: Feb 27 to Mar 13Plant for fall: Aug 28 to Sep 18
Start indoors: Jan 30 to Feb 13Transplant outside: Mar 13 to Mar 27Plant for fall: Jul 31 to Aug 21
Start indoors: Jan 30 to Feb 13Transplant outside: Mar 6 to Mar 20Plant for fall: Jul 31 to Aug 21
Start indoors: Jan 30 to Feb 13Transplant outside: Mar 13 to Mar 27Plant for fall: Jul 31 to Aug 21
Start indoors: Feb 13 to Feb 27Transplant outside: Apr 17 to May 1Sow outdoors: Apr 17 to May 1
Start indoors: Feb 13 to Feb 27Transplant outside: Apr 3 to Apr 17
Sow outdoors: Feb 13 to Mar 6Plant for fall: Aug 14 to Sep 4
Sow outdoors: Feb 13 to Mar 6Plant for fall: Sep 11 to Oct 2
Sow outdoors: Feb 20 to Apr 3Plant for fall: Sep 25 to Oct 16
Start indoors: Feb 27 to Mar 6Transplant outside: Apr 10 to Apr 17Sow outdoors: Apr 3 to Apr 17Plant for fall: Aug 21 to Sep 4
Start indoors: Feb 27 to Mar 6Sow outdoors: Apr 3 to Apr 17Plant for fall: Aug 28 to Sep 11
Start indoors: Feb 27 to Mar 6Sow outdoors: Apr 3 to Apr 17
Start indoors: Feb 27 to Mar 6Transplant outside: Apr 10 to Apr 24
Sow outdoors: Mar 6 to Apr 3Plant for fall: Aug 14 to Aug 28
Sow outdoors: Mar 6 to Apr 3Plant for fall: Aug 28 to Sep 11
Sow outdoors: Mar 6 to Mar 27
Sow outdoors: Mar 13 to Apr 10Plant for fall: Aug 28 to Sep 11
Sow outdoors: Mar 13 to Apr 3Plant for fall: Sep 11 to Oct 2
Sow outdoors: Apr 3 to Apr 24Plant for fall: Aug 21 to Sep 4
Sow outdoors: Apr 3 to Apr 17
Transplant outside: Apr 10 to May 1
Plant for fall: Oct 23 to Nov 27
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Mount Vernon, WA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 2 – Jan 16 | Feb 27 – Mar 13 | — | — |
| Peppers | Jan 16 – Jan 30 | Apr 10 – Apr 24 | — | — |
| Eggplant | Jan 16 – Jan 30 | Apr 10 – Apr 24 | — | — |
| Tomatoes | Jan 30 – Feb 13 | Apr 3 – Apr 17 | — | — |
| Lettuce | Jan 30 – Feb 13 | Mar 6 – Mar 20 | Feb 27 – Apr 3 | Sep 11 – Oct 9 |
| Kale | Jan 30 – Feb 13 | Feb 27 – Mar 13 | Feb 27 – Mar 13 | Aug 28 – Sep 18 |
| Broccoli | Jan 30 – Feb 13 | Mar 13 – Mar 27 | — | Jul 31 – Aug 21 |
| Cabbage | Jan 30 – Feb 13 | Mar 6 – Mar 20 | — | Jul 31 – Aug 21 |
| Cauliflower | Jan 30 – Feb 13 | Mar 13 – Mar 27 | — | Jul 31 – Aug 21 |
| Okra | Feb 13 – Feb 27 | Apr 17 – May 1 | Apr 17 – May 1 | — |
| Basil | Feb 13 – Feb 27 | Apr 3 – Apr 17 | — | — |
| Peas | — | — | Feb 13 – Mar 6 | Aug 14 – Sep 4 |
| Spinach | — | — | Feb 13 – Mar 6 | Sep 11 – Oct 2 |
| Radishes | — | — | Feb 20 – Apr 3 | Sep 25 – Oct 16 |
| Cucumbers | Feb 27 – Mar 6 | Apr 10 – Apr 17 | Apr 3 – Apr 17 | Aug 21 – Sep 4 |
| Zucchini & Summer Squash | Feb 27 – Mar 6 | — | Apr 3 – Apr 17 | Aug 28 – Sep 11 |
| Winter Squash & Pumpkins | Feb 27 – Mar 6 | — | Apr 3 – Apr 17 | — |
| Melons & Watermelon | Feb 27 – Mar 6 | Apr 10 – Apr 24 | — | — |
| Carrots | — | — | Mar 6 – Apr 3 | Aug 14 – Aug 28 |
| Beets | — | — | Mar 6 – Apr 3 | Aug 28 – Sep 11 |
| Potatoes | — | — | Mar 6 – Mar 27 | — |
| Swiss Chard | — | — | Mar 13 – Apr 10 | Aug 28 – Sep 11 |
| Cilantro | — | — | Mar 13 – Apr 3 | Sep 11 – Oct 2 |
| Green Beans | — | — | Apr 3 – Apr 24 | Aug 21 – Sep 4 |
| Sweet Corn | — | — | Apr 3 – Apr 17 | — |
| Sweet Potatoes | — | Apr 10 – May 1 | — | — |
| Garlic | — | — | — | Oct 23 – Nov 27 |
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 Sedro-Woolley, WA weather station, 16 km away (elevation 59 ft (18 m)).
ZIP codes in Mount Vernon: 98273 98274
Frost dates near Mount Vernon
- Clearlake Mar 27 · Nov 6
- Conway Mar 24 · Nov 3
- Burlington Mar 24 · Nov 3
- Sedro Woolley Mar 27 · Nov 6
- Silvana Apr 22 · Oct 19
- Lyman Mar 27 · Nov 6
- Arlington Apr 22 · Oct 19
- Hamilton Mar 28 · Nov 14
Frequently asked questions
When is the last frost in Mount Vernon, WA?
The median last spring frost in Mount Vernon, WA is March 27. There is still about a 10% chance of frost after April 17, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Mount Vernon, WA?
The median first fall frost is November 6, with about a 10% chance of frost before October 15.
How long is the growing season in Mount Vernon, WA?
About 224 days between the median last spring frost and first fall frost.
What planting zone is Mount Vernon, WA?
Mount Vernon, WA is in USDA hardiness zone 8b.