Sprague, WA frost dates
Last spring frostMay 31median date
First fall frostSep 12median date
Growing season104 daysfrost-free
Hardiness zone6bZone 6b
How Sprague compares
- In 8 years out of 10, the last spring frost in Sprague falls between May 10 and June 28, a 49-day window. The first fall frost falls between August 23 and October 2.
- The median last frost is 40 days later than the Washington median of Apr 21.
- Its 104-day growing season is among the shortest of the 491 Washington places with a regular frost season.
- The last frost is 39 days later than the zone 6b median of Apr 22. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6b chart.
- The weather station records an average of 164 nights a year at or below 32°F.
- Compared with Spokane, WA, 58 km away, the last frost here is 35 days later than there and the growing season is 68 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 10 |
| 50% (median) | May 31 |
| 10% (safe for tender plants) | June 28 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 23 |
| 50% (median) | September 12 |
| 90% (late) | October 2 |
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 Sprague, WA
Sprague, WA frost dates — last frost May 31, first frost Sep 12, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Mar 8 to Mar 22Transplant outside: May 3 to May 17
Start indoors: Mar 22 to Apr 5Transplant outside: Jun 14 to Jun 28
Start indoors: Mar 22 to Apr 5Transplant outside: Jun 14 to Jun 28
Start indoors: Apr 5 to Apr 19Transplant outside: Jun 7 to Jun 21
Start indoors: Apr 5 to Apr 19Transplant outside: May 10 to May 24Sow outdoors: May 3 to Jun 7Plant for fall: Jul 18 to Aug 15
Start indoors: Apr 5 to Apr 19Transplant outside: May 3 to May 17Sow outdoors: May 3 to May 17Plant for fall: Jul 4 to Jul 25
Start indoors: Apr 5 to Apr 19Transplant outside: May 17 to May 31
Start indoors: Apr 5 to Apr 19Transplant outside: May 10 to May 24
Start indoors: Apr 5 to Apr 19Transplant outside: May 17 to May 31
Start indoors: Apr 19 to May 3Transplant outside: Jun 21 to Jul 5Sow outdoors: Jun 21 to Jul 5
Start indoors: Apr 19 to May 3Transplant outside: Jun 7 to Jun 21
Sow outdoors: Apr 19 to May 10Plant for fall: Jun 20 to Jul 11
Sow outdoors: Apr 19 to May 10Plant for fall: Jul 18 to Aug 8
Sow outdoors: Apr 26 to Jun 7Plant for fall: Aug 1 to Aug 22
Start indoors: May 3 to May 10Transplant outside: Jun 14 to Jun 21Sow outdoors: Jun 7 to Jun 21
Start indoors: May 3 to May 10Sow outdoors: Jun 7 to Jun 21
Start indoors: May 3 to May 10Sow outdoors: Jun 7 to Jun 21
Start indoors: May 3 to May 10Transplant outside: Jun 14 to Jun 28
Sow outdoors: May 10 to Jun 7
Sow outdoors: May 10 to Jun 7Plant for fall: Jul 4 to Jul 18
Sow outdoors: May 10 to May 31
Sow outdoors: May 17 to Jun 14Plant for fall: Jul 4 to Jul 18
Sow outdoors: May 17 to Jun 7Plant for fall: Jul 18 to Aug 8
Sow outdoors: Jun 7 to Jun 28
Sow outdoors: Jun 7 to Jun 21
Transplant outside: Jun 14 to Jul 5
Plant for fall: Aug 29 to Oct 3
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Sprague, WA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 8 – Mar 22 | May 3 – May 17 | — | — |
| Peppers | Mar 22 – Apr 5 | Jun 14 – Jun 28 | — | — |
| Eggplant | Mar 22 – Apr 5 | Jun 14 – Jun 28 | — | — |
| Tomatoes | Apr 5 – Apr 19 | Jun 7 – Jun 21 | — | — |
| Lettuce | Apr 5 – Apr 19 | May 10 – May 24 | May 3 – Jun 7 | Jul 18 – Aug 15 |
| Kale | Apr 5 – Apr 19 | May 3 – May 17 | May 3 – May 17 | Jul 4 – Jul 25 |
| Broccoli | Apr 5 – Apr 19 | May 17 – May 31 | — | — |
| Cabbage | Apr 5 – Apr 19 | May 10 – May 24 | — | — |
| Cauliflower | Apr 5 – Apr 19 | May 17 – May 31 | — | — |
| Okra | Apr 19 – May 3 | Jun 21 – Jul 5 | Jun 21 – Jul 5 | — |
| Basil | Apr 19 – May 3 | Jun 7 – Jun 21 | — | — |
| Peas | — | — | Apr 19 – May 10 | Jun 20 – Jul 11 |
| Spinach | — | — | Apr 19 – May 10 | Jul 18 – Aug 8 |
| Radishes | — | — | Apr 26 – Jun 7 | Aug 1 – Aug 22 |
| Cucumbers | May 3 – May 10 | Jun 14 – Jun 21 | Jun 7 – Jun 21 | — |
| Zucchini & Summer Squash | May 3 – May 10 | — | Jun 7 – Jun 21 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 104 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 3 – May 10 | — | Jun 7 – Jun 21 | — |
| Melons & Watermelon | May 3 – May 10 | Jun 14 – Jun 28 | — | — |
| Carrots | — | — | May 10 – Jun 7 | — |
| Beets | — | — | May 10 – Jun 7 | Jul 4 – Jul 18 |
| Potatoes | — | — | May 10 – May 31 | — |
| Swiss Chard | — | — | May 17 – Jun 14 | Jul 4 – Jul 18 |
| Cilantro | — | — | May 17 – Jun 7 | Jul 18 – Aug 8 |
| Green Beans | — | — | Jun 7 – Jun 28 | — |
| Sweet Corn | — | — | Jun 7 – Jun 21 | — |
| Sweet Potatoes Warning: Your frost-free season is about 104 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 14 – Jul 5 | — | — |
| Garlic | — | — | — | Aug 29 – Oct 3 |
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 Harrington, WA weather station, 26 km away (elevation 2,159 ft (658 m)).
Frost dates near Sprague
- Lamont Apr 29 · Oct 4
- Edwall Jun 6 · Sep 11
- Harrington May 31 · Sep 12
- Mohler May 31 · Sep 12
- Cheney May 30 · Sep 4
- Ritzville May 7 · Oct 10
- Medical Lake May 10 · Sep 26
- Lamona May 14 · Sep 26
- Four Lakes Apr 26 · Oct 12
- Malden May 7 · Sep 28
Frequently asked questions
When is the last frost in Sprague, WA?
The median last spring frost in Sprague, WA is May 31. There is still about a 10% chance of frost after June 28, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Sprague, WA?
The median first fall frost is September 12, with about a 10% chance of frost before August 23.
How long is the growing season in Sprague, WA?
About 104 days between the median last spring frost and first fall frost.
What planting zone is Sprague, WA?
Sprague, WA is in USDA hardiness zone 6b.