North Bonneville, WA frost dates
Last spring frostMar 14median date
First fall frostNov 27median date
Growing season258 daysfrost-free
Hardiness zone9aZone 9a
How North Bonneville compares
- In 8 years out of 10, the last spring frost in North Bonneville falls between February 19 and April 4, a 44-day window. The first fall frost falls between November 8 and December 15.
- The median last frost is 38 days earlier than the Washington median of Apr 21.
- Its 258-day growing season is longer than 96% of the 491 Washington places with a regular frost season (state median 182 days).
- The last frost is 11 days later than the zone 9a median of Mar 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 9a chart.
- The weather station records an average of 33 nights a year at or below 32°F.
- Compared with Gresham, OR, 38 km away, the last frost here is 2 days earlier than there and the growing season is 9 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | February 19 |
| 50% (median) | March 14 |
| 10% (safe for tender plants) | April 4 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 8 |
| 50% (median) | November 27 |
| 90% (late) | December 15 |
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 North Bonneville, WA
North Bonneville, WA frost dates — last frost Mar 14, first frost Nov 27, zone 9a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Dec 20 to Jan 3Start indoors: Dec 20 to Jan 3Transplant outside: Feb 14 to Feb 28
Start indoors: Jan 3 to Jan 17Transplant outside: Mar 28 to Apr 11
Start indoors: Jan 3 to Jan 17Transplant outside: Mar 28 to Apr 11
Start indoors: Jan 17 to Jan 31Transplant outside: Mar 21 to Apr 4
Start indoors: Jan 17 to Jan 31Transplant outside: Feb 21 to Mar 7Sow outdoors: Feb 14 to Mar 21Plant for fall: Oct 2 to Oct 30
Start indoors: Jan 17 to Jan 31Transplant outside: Feb 14 to Feb 28Sow outdoors: Feb 14 to Feb 28Plant for fall: Sep 18 to Oct 9
Start indoors: Jan 17 to Jan 31Transplant outside: Feb 28 to Mar 14Plant for fall: Aug 21 to Sep 11
Start indoors: Jan 17 to Jan 31Transplant outside: Feb 21 to Mar 7Plant for fall: Aug 21 to Sep 11
Start indoors: Jan 17 to Jan 31Transplant outside: Feb 28 to Mar 14Plant for fall: Aug 21 to Sep 11
Start indoors: Jan 31 to Feb 14Transplant outside: Apr 4 to Apr 18Sow outdoors: Apr 4 to Apr 18
Start indoors: Jan 31 to Feb 14Transplant outside: Mar 21 to Apr 4
Sow outdoors: Jan 31 to Feb 21Plant for fall: Sep 4 to Sep 25
Sow outdoors: Jan 31 to Feb 21Plant for fall: Oct 2 to Oct 23
Sow outdoors: Feb 7 to Mar 21Plant for fall: Oct 16 to Nov 6
Start indoors: Feb 14 to Feb 21Transplant outside: Mar 28 to Apr 4Sow outdoors: Mar 21 to Apr 4Plant for fall: Sep 11 to Sep 25
Start indoors: Feb 14 to Feb 21Sow outdoors: Mar 21 to Apr 4Plant for fall: Sep 18 to Oct 2
Start indoors: Feb 14 to Feb 21Sow outdoors: Mar 21 to Apr 4
Start indoors: Feb 14 to Feb 21Transplant outside: Mar 28 to Apr 11
Sow outdoors: Feb 21 to Mar 21Plant for fall: Sep 4 to Sep 18
Sow outdoors: Feb 21 to Mar 21Plant for fall: Sep 18 to Oct 2
Sow outdoors: Feb 21 to Mar 14
Sow outdoors: Feb 28 to Mar 28Plant for fall: Sep 18 to Oct 2
Sow outdoors: Feb 28 to Mar 21Plant for fall: Oct 2 to Oct 23
Sow outdoors: Mar 21 to Apr 11Plant for fall: Sep 11 to Sep 25
Sow outdoors: Mar 21 to Apr 4
Transplant outside: Mar 28 to Apr 18
Plant for fall: Nov 13 to Dec 18
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in North Bonneville, WA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Dec 20 – Jan 3 | Feb 14 – Feb 28 | — | — |
| Peppers | Jan 3 – Jan 17 | Mar 28 – Apr 11 | — | — |
| Eggplant | Jan 3 – Jan 17 | Mar 28 – Apr 11 | — | — |
| Tomatoes | Jan 17 – Jan 31 | Mar 21 – Apr 4 | — | — |
| Lettuce | Jan 17 – Jan 31 | Feb 21 – Mar 7 | Feb 14 – Mar 21 | Oct 2 – Oct 30 |
| Kale | Jan 17 – Jan 31 | Feb 14 – Feb 28 | Feb 14 – Feb 28 | Sep 18 – Oct 9 |
| Broccoli | Jan 17 – Jan 31 | Feb 28 – Mar 14 | — | Aug 21 – Sep 11 |
| Cabbage | Jan 17 – Jan 31 | Feb 21 – Mar 7 | — | Aug 21 – Sep 11 |
| Cauliflower | Jan 17 – Jan 31 | Feb 28 – Mar 14 | — | Aug 21 – Sep 11 |
| Okra | Jan 31 – Feb 14 | Apr 4 – Apr 18 | Apr 4 – Apr 18 | — |
| Basil | Jan 31 – Feb 14 | Mar 21 – Apr 4 | — | — |
| Peas | — | — | Jan 31 – Feb 21 | Sep 4 – Sep 25 |
| Spinach | — | — | Jan 31 – Feb 21 | Oct 2 – Oct 23 |
| Radishes | — | — | Feb 7 – Mar 21 | Oct 16 – Nov 6 |
| Cucumbers | Feb 14 – Feb 21 | Mar 28 – Apr 4 | Mar 21 – Apr 4 | Sep 11 – Sep 25 |
| Zucchini & Summer Squash | Feb 14 – Feb 21 | — | Mar 21 – Apr 4 | Sep 18 – Oct 2 |
| Winter Squash & Pumpkins | Feb 14 – Feb 21 | — | Mar 21 – Apr 4 | — |
| Melons & Watermelon | Feb 14 – Feb 21 | Mar 28 – Apr 11 | — | — |
| Carrots | — | — | Feb 21 – Mar 21 | Sep 4 – Sep 18 |
| Beets | — | — | Feb 21 – Mar 21 | Sep 18 – Oct 2 |
| Potatoes | — | — | Feb 21 – Mar 14 | — |
| Swiss Chard | — | — | Feb 28 – Mar 28 | Sep 18 – Oct 2 |
| Cilantro | — | — | Feb 28 – Mar 21 | Oct 2 – Oct 23 |
| Green Beans | — | — | Mar 21 – Apr 11 | Sep 11 – Sep 25 |
| Sweet Corn | — | — | Mar 21 – Apr 4 | — |
| Sweet Potatoes | — | Mar 28 – Apr 18 | — | — |
| Garlic | — | — | — | Nov 13 – Dec 18 |
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 Bonneville Dam, OR weather station, about 1 km away (elevation 62 ft (19 m)).
Frost dates near North Bonneville
- Stevenson Mar 24 · Nov 20
- Carson Mar 24 · Nov 20
- Washougal Apr 29 · Oct 22
- Bingen Apr 20 · Oct 13
- Underwood Apr 20 · Oct 13
- Camas Mar 16 · Nov 20
- White Salmon Apr 20 · Oct 13
- Brush Prairie Apr 26 · Oct 16
- Husum May 12 · Oct 11
- Yacolt Apr 26 · Oct 16
Frequently asked questions
When is the last frost in North Bonneville, WA?
The median last spring frost in North Bonneville, WA is March 14. There is still about a 10% chance of frost after April 4, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in North Bonneville, WA?
The median first fall frost is November 27, with about a 10% chance of frost before November 8.
How long is the growing season in North Bonneville, WA?
About 258 days between the median last spring frost and first fall frost.
What planting zone is North Bonneville, WA?
North Bonneville, WA is in USDA hardiness zone 9a.