Ephrata, WA frost dates
Last spring frostApr 22median date
First fall frostOct 17median date
Growing season178 daysfrost-free
Hardiness zone6bZone 6b
How Ephrata compares
- In 8 years out of 10, the last spring frost in Ephrata falls between April 8 and May 6, a 28-day window. The first fall frost falls between October 3 and October 28.
- The median last frost is 1 day later than the Washington median of Apr 21.
- Its 178-day growing season is longer than 43% of the 491 Washington places with a regular frost season (state median 182 days).
- The last frost is typical for zone 6b, where the median is Apr 22.
- The weather station records an average of 121 nights a year at or below 32°F.
- Compared with Richland, WA, 111 km away, the last frost here is 16 days later than there and the growing season is 23 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 8 |
| 50% (median) | April 22 |
| 10% (safe for tender plants) | May 6 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 3 |
| 50% (median) | October 17 |
| 90% (late) | October 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 Ephrata, WA
Ephrata, WA frost dates — last frost Apr 22, first frost Oct 17, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Jan 28 to Feb 11Transplant outside: Mar 25 to Apr 8
Start indoors: Feb 11 to Feb 25Transplant outside: May 6 to May 20
Start indoors: Feb 11 to Feb 25Transplant outside: May 6 to May 20
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 29 to May 13
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 1 to Apr 15Sow outdoors: Mar 25 to Apr 29Plant for fall: Aug 22 to Sep 19
Start indoors: Feb 25 to Mar 11Transplant outside: Mar 25 to Apr 8Sow outdoors: Mar 25 to Apr 8Plant for fall: Aug 8 to Aug 29
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 8 to Apr 22Plant for fall: Jul 11 to Aug 1
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 1 to Apr 15Plant for fall: Jul 11 to Aug 1
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 8 to Apr 22Plant for fall: Jul 11 to Aug 1
Start indoors: Mar 11 to Mar 25Transplant outside: May 13 to May 27Sow outdoors: May 13 to May 27
Start indoors: Mar 11 to Mar 25Transplant outside: Apr 29 to May 13
Sow outdoors: Mar 11 to Apr 1Plant for fall: Jul 25 to Aug 15
Sow outdoors: Mar 11 to Apr 1Plant for fall: Aug 22 to Sep 12
Sow outdoors: Mar 18 to Apr 29Plant for fall: Sep 5 to Sep 26
Start indoors: Mar 25 to Apr 1Transplant outside: May 6 to May 13Sow outdoors: Apr 29 to May 13Plant for fall: Aug 1 to Aug 15
Start indoors: Mar 25 to Apr 1Sow outdoors: Apr 29 to May 13Plant for fall: Aug 8 to Aug 22
Start indoors: Mar 25 to Apr 1Sow outdoors: Apr 29 to May 13
Start indoors: Mar 25 to Apr 1Transplant outside: May 6 to May 20
Sow outdoors: Apr 1 to Apr 29Plant for fall: Jul 25 to Aug 8
Sow outdoors: Apr 1 to Apr 29Plant for fall: Aug 8 to Aug 22
Sow outdoors: Apr 1 to Apr 22
Sow outdoors: Apr 8 to May 6Plant for fall: Aug 8 to Aug 22
Sow outdoors: Apr 8 to Apr 29Plant for fall: Aug 22 to Sep 12
Sow outdoors: Apr 29 to May 20Plant for fall: Aug 1 to Aug 15
Sow outdoors: Apr 29 to May 13
Transplant outside: May 6 to May 27
Plant for fall: Oct 3 to Nov 7
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Ephrata, WA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 28 – Feb 11 | Mar 25 – Apr 8 | — | — |
| Peppers | Feb 11 – Feb 25 | May 6 – May 20 | — | — |
| Eggplant | Feb 11 – Feb 25 | May 6 – May 20 | — | — |
| Tomatoes | Feb 25 – Mar 11 | Apr 29 – May 13 | — | — |
| Lettuce | Feb 25 – Mar 11 | Apr 1 – Apr 15 | Mar 25 – Apr 29 | Aug 22 – Sep 19 |
| Kale | Feb 25 – Mar 11 | Mar 25 – Apr 8 | Mar 25 – Apr 8 | Aug 8 – Aug 29 |
| Broccoli | Feb 25 – Mar 11 | Apr 8 – Apr 22 | — | Jul 11 – Aug 1 |
| Cabbage | Feb 25 – Mar 11 | Apr 1 – Apr 15 | — | Jul 11 – Aug 1 |
| Cauliflower | Feb 25 – Mar 11 | Apr 8 – Apr 22 | — | Jul 11 – Aug 1 |
| Okra | Mar 11 – Mar 25 | May 13 – May 27 | May 13 – May 27 | — |
| Basil | Mar 11 – Mar 25 | Apr 29 – May 13 | — | — |
| Peas | — | — | Mar 11 – Apr 1 | Jul 25 – Aug 15 |
| Spinach | — | — | Mar 11 – Apr 1 | Aug 22 – Sep 12 |
| Radishes | — | — | Mar 18 – Apr 29 | Sep 5 – Sep 26 |
| Cucumbers | Mar 25 – Apr 1 | May 6 – May 13 | Apr 29 – May 13 | Aug 1 – Aug 15 |
| Zucchini & Summer Squash | Mar 25 – Apr 1 | — | Apr 29 – May 13 | Aug 8 – Aug 22 |
| Winter Squash & Pumpkins | Mar 25 – Apr 1 | — | Apr 29 – May 13 | — |
| Melons & Watermelon | Mar 25 – Apr 1 | May 6 – May 20 | — | — |
| Carrots | — | — | Apr 1 – Apr 29 | Jul 25 – Aug 8 |
| Beets | — | — | Apr 1 – Apr 29 | Aug 8 – Aug 22 |
| Potatoes | — | — | Apr 1 – Apr 22 | — |
| Swiss Chard | — | — | Apr 8 – May 6 | Aug 8 – Aug 22 |
| Cilantro | — | — | Apr 8 – Apr 29 | Aug 22 – Sep 12 |
| Green Beans | — | — | Apr 29 – May 20 | Aug 1 – Aug 15 |
| Sweet Corn | — | — | Apr 29 – May 13 | — |
| Sweet Potatoes | — | May 6 – May 27 | — | — |
| Garlic | — | — | — | Oct 3 – Nov 7 |
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 Ephrata Muni Ap, WA weather station, 4 km away (elevation 1,253 ft (382 m)).
Frost dates near Ephrata
- Soap Lake Apr 22 · Oct 17
- Moses Lake Apr 27 · Oct 8
- Quincy Apr 21 · Oct 16
- Stratford Apr 22 · Oct 17
- Palisades Apr 8 · Oct 24
- George Apr 21 · Oct 16
- Wilson Creek May 2 · Oct 12
- Marlin Apr 27 · Oct 8
- Royal City Apr 23 · Oct 12
- Coulee City May 2 · Oct 12
Frequently asked questions
When is the last frost in Ephrata, WA?
The median last spring frost in Ephrata, WA is April 22. There is still about a 10% chance of frost after May 6, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Ephrata, WA?
The median first fall frost is October 17, with about a 10% chance of frost before October 3.
How long is the growing season in Ephrata, WA?
About 178 days between the median last spring frost and first fall frost.
What planting zone is Ephrata, WA?
Ephrata, WA is in USDA hardiness zone 6b.