Wilsonville, OR frost dates
Last spring frostMar 18median date
First fall frostNov 13median date
Growing season240 daysfrost-free
Hardiness zone8bZone 8b
How Wilsonville compares
- In 8 years out of 10, the last spring frost in Wilsonville falls between February 22 and April 10, a 47-day window. The first fall frost falls between October 27 and December 6.
- The median last frost is 29 days earlier than the Oregon median of Apr 16.
- Its 240-day growing season is longer than 81% of the 345 Oregon places with a regular frost season (state median 193 days).
- The last frost is typical for zone 8b, where the median is Mar 16.
- The weather station records an average of 45 nights a year at or below 32°F.
- Compared with Beaverton, OR, 21 km away, the last frost here is 35 days later than there and the growing season is 57 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | February 22 |
| 50% (median) | March 18 |
| 10% (safe for tender plants) | April 10 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 27 |
| 50% (median) | November 13 |
| 90% (late) | December 6 |
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 Wilsonville, OR
Wilsonville, OR frost dates — last frost Mar 18, first frost Nov 13, zone 8b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Dec 24 to Jan 7Start indoors: Dec 24 to Jan 7Transplant outside: Feb 18 to Mar 4
Start indoors: Jan 7 to Jan 21Transplant outside: Apr 1 to Apr 15
Start indoors: Jan 7 to Jan 21Transplant outside: Apr 1 to Apr 15
Start indoors: Jan 21 to Feb 4Transplant outside: Mar 25 to Apr 8
Start indoors: Jan 21 to Feb 4Transplant outside: Feb 25 to Mar 11Sow outdoors: Feb 18 to Mar 25Plant for fall: Sep 18 to Oct 16
Start indoors: Jan 21 to Feb 4Transplant outside: Feb 18 to Mar 4Sow outdoors: Feb 18 to Mar 4Plant for fall: Sep 4 to Sep 25
Start indoors: Jan 21 to Feb 4Transplant outside: Mar 4 to Mar 18Plant for fall: Aug 7 to Aug 28
Start indoors: Jan 21 to Feb 4Transplant outside: Feb 25 to Mar 11Plant for fall: Aug 7 to Aug 28
Start indoors: Jan 21 to Feb 4Transplant outside: Mar 4 to Mar 18Plant for fall: Aug 7 to Aug 28
Start indoors: Feb 4 to Feb 18Transplant outside: Apr 8 to Apr 22Sow outdoors: Apr 8 to Apr 22
Start indoors: Feb 4 to Feb 18Transplant outside: Mar 25 to Apr 8
Sow outdoors: Feb 4 to Feb 25Plant for fall: Aug 21 to Sep 11
Sow outdoors: Feb 4 to Feb 25Plant for fall: Sep 18 to Oct 9
Sow outdoors: Feb 11 to Mar 25Plant for fall: Oct 2 to Oct 23
Start indoors: Feb 18 to Feb 25Transplant outside: Apr 1 to Apr 8Sow outdoors: Mar 25 to Apr 8Plant for fall: Aug 28 to Sep 11
Start indoors: Feb 18 to Feb 25Sow outdoors: Mar 25 to Apr 8Plant for fall: Sep 4 to Sep 18
Start indoors: Feb 18 to Feb 25Sow outdoors: Mar 25 to Apr 8
Start indoors: Feb 18 to Feb 25Transplant outside: Apr 1 to Apr 15
Sow outdoors: Feb 25 to Mar 25Plant for fall: Aug 21 to Sep 4
Sow outdoors: Feb 25 to Mar 25Plant for fall: Sep 4 to Sep 18
Sow outdoors: Feb 25 to Mar 18
Sow outdoors: Mar 4 to Apr 1Plant for fall: Sep 4 to Sep 18
Sow outdoors: Mar 4 to Mar 25Plant for fall: Sep 18 to Oct 9
Sow outdoors: Mar 25 to Apr 15Plant for fall: Aug 28 to Sep 11
Sow outdoors: Mar 25 to Apr 8
Transplant outside: Apr 1 to Apr 22
Plant for fall: Oct 30 to Dec 4
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Wilsonville, OR
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Dec 24 – Jan 7 | Feb 18 – Mar 4 | — | — |
| Peppers | Jan 7 – Jan 21 | Apr 1 – Apr 15 | — | — |
| Eggplant | Jan 7 – Jan 21 | Apr 1 – Apr 15 | — | — |
| Tomatoes | Jan 21 – Feb 4 | Mar 25 – Apr 8 | — | — |
| Lettuce | Jan 21 – Feb 4 | Feb 25 – Mar 11 | Feb 18 – Mar 25 | Sep 18 – Oct 16 |
| Kale | Jan 21 – Feb 4 | Feb 18 – Mar 4 | Feb 18 – Mar 4 | Sep 4 – Sep 25 |
| Broccoli | Jan 21 – Feb 4 | Mar 4 – Mar 18 | — | Aug 7 – Aug 28 |
| Cabbage | Jan 21 – Feb 4 | Feb 25 – Mar 11 | — | Aug 7 – Aug 28 |
| Cauliflower | Jan 21 – Feb 4 | Mar 4 – Mar 18 | — | Aug 7 – Aug 28 |
| Okra | Feb 4 – Feb 18 | Apr 8 – Apr 22 | Apr 8 – Apr 22 | — |
| Basil | Feb 4 – Feb 18 | Mar 25 – Apr 8 | — | — |
| Peas | — | — | Feb 4 – Feb 25 | Aug 21 – Sep 11 |
| Spinach | — | — | Feb 4 – Feb 25 | Sep 18 – Oct 9 |
| Radishes | — | — | Feb 11 – Mar 25 | Oct 2 – Oct 23 |
| Cucumbers | Feb 18 – Feb 25 | Apr 1 – Apr 8 | Mar 25 – Apr 8 | Aug 28 – Sep 11 |
| Zucchini & Summer Squash | Feb 18 – Feb 25 | — | Mar 25 – Apr 8 | Sep 4 – Sep 18 |
| Winter Squash & Pumpkins | Feb 18 – Feb 25 | — | Mar 25 – Apr 8 | — |
| Melons & Watermelon | Feb 18 – Feb 25 | Apr 1 – Apr 15 | — | — |
| Carrots | — | — | Feb 25 – Mar 25 | Aug 21 – Sep 4 |
| Beets | — | — | Feb 25 – Mar 25 | Sep 4 – Sep 18 |
| Potatoes | — | — | Feb 25 – Mar 18 | — |
| Swiss Chard | — | — | Mar 4 – Apr 1 | Sep 4 – Sep 18 |
| Cilantro | — | — | Mar 4 – Mar 25 | Sep 18 – Oct 9 |
| Green Beans | — | — | Mar 25 – Apr 15 | Aug 28 – Sep 11 |
| Sweet Corn | — | — | Mar 25 – Apr 8 | — |
| Sweet Potatoes | — | Apr 1 – Apr 22 | — | — |
| Garlic | — | — | — | Oct 30 – Dec 4 |
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 N Willamette Exp Stn, OR weather station, 2 km away (elevation 151 ft (46 m)).
Frost dates near Wilsonville
- Tualatin Apr 1 · Nov 6
- Aurora Mar 16 · Nov 14
- Canby Mar 18 · Nov 13
- Sherwood Mar 21 · Nov 22
- Donald Mar 16 · Nov 14
- West Linn Mar 18 · Nov 18
- Hubbard Mar 16 · Nov 14
- Lake Oswego Mar 18 · Nov 18
- Marylhurst Mar 18 · Nov 18
- Newberg Mar 21 · Nov 22
Frequently asked questions
When is the last frost in Wilsonville, OR?
The median last spring frost in Wilsonville, OR is March 18. There is still about a 10% chance of frost after April 10, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Wilsonville, OR?
The median first fall frost is November 13, with about a 10% chance of frost before October 27.
How long is the growing season in Wilsonville, OR?
About 240 days between the median last spring frost and first fall frost.
What planting zone is Wilsonville, OR?
Wilsonville, OR is in USDA hardiness zone 8b.