Morton, WA frost dates
Last spring frostApr 24median date
First fall frostOct 15median date
Growing season174 daysfrost-free
Hardiness zone8bZone 8b
How Morton compares
- In 8 years out of 10, the last spring frost in Morton falls between March 31 and May 12, a 42-day window. The first fall frost falls between September 24 and November 8.
- The median last frost is 3 days later than the Washington median of Apr 21.
- Its 174-day growing season is longer than 38% of the 491 Washington places with a regular frost season (state median 182 days).
- The last frost is 39 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 82 nights a year at or below 32°F.
- Compared with Lakewood, WA, 70 km away, the last frost here is 47 days later than there and the growing season is 77 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 31 |
| 50% (median) | April 24 |
| 10% (safe for tender plants) | May 12 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 24 |
| 50% (median) | October 15 |
| 90% (late) | November 8 |
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 Morton, WA
Morton, WA frost dates — last frost Apr 24, first frost Oct 15, zone 8b. whenisthelastfrost.com
Crop
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Start indoors: Jan 30 to Feb 13Transplant outside: Mar 27 to Apr 10
Start indoors: Feb 13 to Feb 27Transplant outside: May 8 to May 22
Start indoors: Feb 13 to Feb 27Transplant outside: May 8 to May 22
Start indoors: Feb 27 to Mar 13Transplant outside: May 1 to May 15
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 3 to Apr 17Sow outdoors: Mar 27 to May 1Plant for fall: Aug 20 to Sep 17
Start indoors: Feb 27 to Mar 13Transplant outside: Mar 27 to Apr 10Sow outdoors: Mar 27 to Apr 10Plant for fall: Aug 6 to Aug 27
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 10 to Apr 24Plant for fall: Jul 9 to Jul 30
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 3 to Apr 17Plant for fall: Jul 9 to Jul 30
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 10 to Apr 24Plant for fall: Jul 9 to Jul 30
Start indoors: Mar 13 to Mar 27Transplant outside: May 15 to May 29Sow outdoors: May 15 to May 29
Start indoors: Mar 13 to Mar 27Transplant outside: May 1 to May 15
Sow outdoors: Mar 13 to Apr 3Plant for fall: Jul 23 to Aug 13
Sow outdoors: Mar 13 to Apr 3Plant for fall: Aug 20 to Sep 10
Sow outdoors: Mar 20 to May 1Plant for fall: Sep 3 to Sep 24
Start indoors: Mar 27 to Apr 3Transplant outside: May 8 to May 15Sow outdoors: May 1 to May 15Plant for fall: Jul 30 to Aug 13
Start indoors: Mar 27 to Apr 3Sow outdoors: May 1 to May 15Plant for fall: Aug 6 to Aug 20
Start indoors: Mar 27 to Apr 3Sow outdoors: May 1 to May 15
Start indoors: Mar 27 to Apr 3Transplant outside: May 8 to May 22
Sow outdoors: Apr 3 to May 1Plant for fall: Jul 23 to Aug 6
Sow outdoors: Apr 3 to May 1Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 3 to Apr 24
Sow outdoors: Apr 10 to May 8Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 10 to May 1Plant for fall: Aug 20 to Sep 10
Sow outdoors: May 1 to May 22Plant for fall: Jul 30 to Aug 13
Sow outdoors: May 1 to May 15
Transplant outside: May 8 to May 29
Plant for fall: Oct 1 to Nov 5
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Morton, WA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 30 – Feb 13 | Mar 27 – Apr 10 | — | — |
| Peppers | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Eggplant | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Tomatoes | Feb 27 – Mar 13 | May 1 – May 15 | — | — |
| Lettuce | Feb 27 – Mar 13 | Apr 3 – Apr 17 | Mar 27 – May 1 | Aug 20 – Sep 17 |
| Kale | Feb 27 – Mar 13 | Mar 27 – Apr 10 | Mar 27 – Apr 10 | Aug 6 – Aug 27 |
| Broccoli | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 9 – Jul 30 |
| Cabbage | Feb 27 – Mar 13 | Apr 3 – Apr 17 | — | Jul 9 – Jul 30 |
| Cauliflower | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 9 – Jul 30 |
| Okra | Mar 13 – Mar 27 | May 15 – May 29 | May 15 – May 29 | — |
| Basil | Mar 13 – Mar 27 | May 1 – May 15 | — | — |
| Peas | — | — | Mar 13 – Apr 3 | Jul 23 – Aug 13 |
| Spinach | — | — | Mar 13 – Apr 3 | Aug 20 – Sep 10 |
| Radishes | — | — | Mar 20 – May 1 | Sep 3 – Sep 24 |
| Cucumbers | Mar 27 – Apr 3 | May 8 – May 15 | May 1 – May 15 | Jul 30 – Aug 13 |
| Zucchini & Summer Squash | Mar 27 – Apr 3 | — | May 1 – May 15 | Aug 6 – Aug 20 |
| Winter Squash & Pumpkins | Mar 27 – Apr 3 | — | May 1 – May 15 | — |
| Melons & Watermelon | Mar 27 – Apr 3 | May 8 – May 22 | — | — |
| Carrots | — | — | Apr 3 – May 1 | Jul 23 – Aug 6 |
| Beets | — | — | Apr 3 – May 1 | Aug 6 – Aug 20 |
| Potatoes | — | — | Apr 3 – Apr 24 | — |
| Swiss Chard | — | — | Apr 10 – May 8 | Aug 6 – Aug 20 |
| Cilantro | — | — | Apr 10 – May 1 | Aug 20 – Sep 10 |
| Green Beans | — | — | May 1 – May 22 | Jul 30 – Aug 13 |
| Sweet Corn | — | — | May 1 – May 15 | — |
| Sweet Potatoes | — | May 8 – May 29 | — | — |
| Garlic | — | — | — | Oct 1 – Nov 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 Glenoma, WA weather station, 10 km away (elevation 840 ft (256 m)).
Frost dates near Morton
- Glenoma Apr 24 · Oct 15
- Silver Creek Apr 7 · Nov 13
- Mineral Apr 24 · Oct 15
- Mossyrock Apr 7 · Nov 13
- Cinebar Apr 7 · Nov 13
- Elbe Apr 24 · Oct 15
- Salkum Apr 7 · Nov 13
- Ashford May 22 · Oct 3
- Randle Apr 30 · Oct 8
- La Grande Apr 11 · Oct 30
Frequently asked questions
When is the last frost in Morton, WA?
The median last spring frost in Morton, WA is April 24. There is still about a 10% chance of frost after May 12, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Morton, WA?
The median first fall frost is October 15, with about a 10% chance of frost before September 24.
How long is the growing season in Morton, WA?
About 174 days between the median last spring frost and first fall frost.
What planting zone is Morton, WA?
Morton, WA is in USDA hardiness zone 8b.