Colton, WA frost dates
Last spring frostApr 29median date
First fall frostOct 2median date
Growing season156 daysfrost-free
Hardiness zone7aZone 7a
How Colton compares
- In 8 years out of 10, the last spring frost in Colton falls between April 7 and May 14, a 37-day window. The first fall frost falls between September 17 and October 25.
- The median last frost is 8 days later than the Washington median of Apr 21.
- Its 156-day growing season is longer than 23% of the 491 Washington places with a regular frost season (state median 182 days).
- The last frost is 13 days later than the zone 7a median of Apr 16. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 7a chart.
- The weather station records an average of 119 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 7 |
| 50% (median) | April 29 |
| 10% (safe for tender plants) | May 14 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 17 |
| 50% (median) | October 2 |
| 90% (late) | October 25 |
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 Colton, WA
Colton, WA frost dates — last frost Apr 29, first frost Oct 2, zone 7a. whenisthelastfrost.com
Crop
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Start indoors: Feb 4 to Feb 18Transplant outside: Apr 1 to Apr 15
Start indoors: Feb 18 to Mar 4Transplant outside: May 13 to May 27
Start indoors: Feb 18 to Mar 4Transplant outside: May 13 to May 27
Start indoors: Mar 4 to Mar 18Transplant outside: May 6 to May 20
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 8 to Apr 22Sow outdoors: Apr 1 to May 6Plant for fall: Aug 7 to Sep 4
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 1 to Apr 15Sow outdoors: Apr 1 to Apr 15Plant for fall: Jul 24 to Aug 14
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 15 to Apr 29Plant for fall: Jun 26 to Jul 17
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 8 to Apr 22Plant for fall: Jun 26 to Jul 17
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 15 to Apr 29Plant for fall: Jun 26 to Jul 17
Start indoors: Mar 18 to Apr 1Transplant outside: May 20 to Jun 3Sow outdoors: May 20 to Jun 3
Start indoors: Mar 18 to Apr 1Transplant outside: May 6 to May 20
Sow outdoors: Mar 18 to Apr 8Plant for fall: Jul 10 to Jul 31
Sow outdoors: Mar 18 to Apr 8Plant for fall: Aug 7 to Aug 28
Sow outdoors: Mar 25 to May 6Plant for fall: Aug 21 to Sep 11
Start indoors: Apr 1 to Apr 8Transplant outside: May 13 to May 20Sow outdoors: May 6 to May 20Plant for fall: Jul 17 to Jul 31
Start indoors: Apr 1 to Apr 8Sow outdoors: May 6 to May 20Plant for fall: Jul 24 to Aug 7
Start indoors: Apr 1 to Apr 8Sow outdoors: May 6 to May 20
Start indoors: Apr 1 to Apr 8Transplant outside: May 13 to May 27
Sow outdoors: Apr 8 to May 6Plant for fall: Jul 10 to Jul 24
Sow outdoors: Apr 8 to May 6Plant for fall: Jul 24 to Aug 7
Sow outdoors: Apr 8 to Apr 29
Sow outdoors: Apr 15 to May 13Plant for fall: Jul 24 to Aug 7
Sow outdoors: Apr 15 to May 6Plant for fall: Aug 7 to Aug 28
Sow outdoors: May 6 to May 27Plant for fall: Jul 17 to Jul 31
Sow outdoors: May 6 to May 20
Transplant outside: May 13 to Jun 3
Plant for fall: Sep 18 to Oct 23
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Colton, WA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 4 – Feb 18 | Apr 1 – Apr 15 | — | — |
| Peppers | Feb 18 – Mar 4 | May 13 – May 27 | — | — |
| Eggplant | Feb 18 – Mar 4 | May 13 – May 27 | — | — |
| Tomatoes | Mar 4 – Mar 18 | May 6 – May 20 | — | — |
| Lettuce | Mar 4 – Mar 18 | Apr 8 – Apr 22 | Apr 1 – May 6 | Aug 7 – Sep 4 |
| Kale | Mar 4 – Mar 18 | Apr 1 – Apr 15 | Apr 1 – Apr 15 | Jul 24 – Aug 14 |
| Broccoli | Mar 4 – Mar 18 | Apr 15 – Apr 29 | — | Jun 26 – Jul 17 |
| Cabbage | Mar 4 – Mar 18 | Apr 8 – Apr 22 | — | Jun 26 – Jul 17 |
| Cauliflower | Mar 4 – Mar 18 | Apr 15 – Apr 29 | — | Jun 26 – Jul 17 |
| Okra | Mar 18 – Apr 1 | May 20 – Jun 3 | May 20 – Jun 3 | — |
| Basil | Mar 18 – Apr 1 | May 6 – May 20 | — | — |
| Peas | — | — | Mar 18 – Apr 8 | Jul 10 – Jul 31 |
| Spinach | — | — | Mar 18 – Apr 8 | Aug 7 – Aug 28 |
| Radishes | — | — | Mar 25 – May 6 | Aug 21 – Sep 11 |
| Cucumbers | Apr 1 – Apr 8 | May 13 – May 20 | May 6 – May 20 | Jul 17 – Jul 31 |
| Zucchini & Summer Squash | Apr 1 – Apr 8 | — | May 6 – May 20 | Jul 24 – Aug 7 |
| Winter Squash & Pumpkins | Apr 1 – Apr 8 | — | May 6 – May 20 | — |
| Melons & Watermelon | Apr 1 – Apr 8 | May 13 – May 27 | — | — |
| Carrots | — | — | Apr 8 – May 6 | Jul 10 – Jul 24 |
| Beets | — | — | Apr 8 – May 6 | Jul 24 – Aug 7 |
| Potatoes | — | — | Apr 8 – Apr 29 | — |
| Swiss Chard | — | — | Apr 15 – May 13 | Jul 24 – Aug 7 |
| Cilantro | — | — | Apr 15 – May 6 | Aug 7 – Aug 28 |
| Green Beans | — | — | May 6 – May 27 | Jul 17 – Jul 31 |
| Sweet Corn | — | — | May 6 – May 20 | — |
| Sweet Potatoes | — | May 13 – Jun 3 | — | — |
| Garlic | — | — | — | Sep 18 – Oct 23 |
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 Pullman Moscow Rgnl Ap, WA weather station, 18 km away (elevation 2,552 ft (778 m)).
Frost dates near Colton
- Uniontown Apr 6 · Oct 26
- Pullman May 6 · Sep 29
- Clarkston Apr 6 · Oct 26
- Albion May 6 · Sep 29
- Pomeroy May 2 · Oct 4
- Colfax May 6 · Sep 29
- Palouse May 6 · Sep 29
- Garfield May 15 · Sep 21
- Steptoe Apr 29 · Oct 4
- Lacrosse May 13 · Sep 26
Frequently asked questions
When is the last frost in Colton, WA?
The median last spring frost in Colton, WA is April 29. There is still about a 10% chance of frost after May 14, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Colton, WA?
The median first fall frost is October 2, with about a 10% chance of frost before September 17.
How long is the growing season in Colton, WA?
About 156 days between the median last spring frost and first fall frost.
What planting zone is Colton, WA?
Colton, WA is in USDA hardiness zone 7a.