Tumtum, WA frost dates
Last spring frostMay 10median date
First fall frostSep 26median date
Growing season139 daysfrost-free
Hardiness zone6bZone 6b
How Tumtum compares
- In 8 years out of 10, the last spring frost in Tumtum falls between April 25 and May 30, a 35-day window. The first fall frost falls between September 11 and October 8.
- The median last frost is 19 days later than the Washington median of Apr 21.
- Its 139-day growing season is longer than 11% of the 491 Washington places with a regular frost season (state median 182 days).
- The last frost is 18 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 157 nights a year at or below 32°F.
- Compared with Spokane, WA, 37 km away, the last frost here is 14 days later than there and the growing season is 33 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 25 |
| 50% (median) | May 10 |
| 10% (safe for tender plants) | May 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 11 |
| 50% (median) | September 26 |
| 90% (late) | October 8 |
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 Tumtum, WA
Tumtum, WA frost dates — last frost May 10, first frost Sep 26, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Feb 15 to Mar 1Transplant outside: Apr 12 to Apr 26
Start indoors: Mar 1 to Mar 15Transplant outside: May 24 to Jun 7
Start indoors: Mar 1 to Mar 15Transplant outside: May 24 to Jun 7
Start indoors: Mar 15 to Mar 29Transplant outside: May 17 to May 31
Start indoors: Mar 15 to Mar 29Transplant outside: Apr 19 to May 3Sow outdoors: Apr 12 to May 17Plant for fall: Aug 1 to Aug 29
Start indoors: Mar 15 to Mar 29Transplant outside: Apr 12 to Apr 26Sow outdoors: Apr 12 to Apr 26Plant for fall: Jul 18 to Aug 8
Start indoors: Mar 15 to Mar 29Transplant outside: Apr 26 to May 10Plant for fall: Jun 20 to Jul 11
Start indoors: Mar 15 to Mar 29Transplant outside: Apr 19 to May 3Plant for fall: Jun 20 to Jul 11
Start indoors: Mar 15 to Mar 29Transplant outside: Apr 26 to May 10Plant for fall: Jun 20 to Jul 11
Start indoors: Mar 29 to Apr 12Transplant outside: May 31 to Jun 14Sow outdoors: May 31 to Jun 14
Start indoors: Mar 29 to Apr 12Transplant outside: May 17 to May 31
Sow outdoors: Mar 29 to Apr 19Plant for fall: Jul 4 to Jul 25
Sow outdoors: Mar 29 to Apr 19Plant for fall: Aug 1 to Aug 22
Sow outdoors: Apr 5 to May 17Plant for fall: Aug 15 to Sep 5
Start indoors: Apr 12 to Apr 19Transplant outside: May 24 to May 31Sow outdoors: May 17 to May 31Plant for fall: Jul 11 to Jul 25
Start indoors: Apr 12 to Apr 19Sow outdoors: May 17 to May 31Plant for fall: Jul 18 to Aug 1
Start indoors: Apr 12 to Apr 19Sow outdoors: May 17 to May 31
Start indoors: Apr 12 to Apr 19Transplant outside: May 24 to Jun 7
Sow outdoors: Apr 19 to May 17Plant for fall: Jul 4 to Jul 18
Sow outdoors: Apr 19 to May 17Plant for fall: Jul 18 to Aug 1
Sow outdoors: Apr 19 to May 10
Sow outdoors: Apr 26 to May 24Plant for fall: Jul 18 to Aug 1
Sow outdoors: Apr 26 to May 17Plant for fall: Aug 1 to Aug 22
Sow outdoors: May 17 to Jun 7Plant for fall: Jul 11 to Jul 25
Sow outdoors: May 17 to May 31
Transplant outside: May 24 to Jun 14
Plant for fall: Sep 12 to Oct 17
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Tumtum, WA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 15 – Mar 1 | Apr 12 – Apr 26 | — | — |
| Peppers | Mar 1 – Mar 15 | May 24 – Jun 7 | — | — |
| Eggplant | Mar 1 – Mar 15 | May 24 – Jun 7 | — | — |
| Tomatoes | Mar 15 – Mar 29 | May 17 – May 31 | — | — |
| Lettuce | Mar 15 – Mar 29 | Apr 19 – May 3 | Apr 12 – May 17 | Aug 1 – Aug 29 |
| Kale | Mar 15 – Mar 29 | Apr 12 – Apr 26 | Apr 12 – Apr 26 | Jul 18 – Aug 8 |
| Broccoli | Mar 15 – Mar 29 | Apr 26 – May 10 | — | Jun 20 – Jul 11 |
| Cabbage | Mar 15 – Mar 29 | Apr 19 – May 3 | — | Jun 20 – Jul 11 |
| Cauliflower | Mar 15 – Mar 29 | Apr 26 – May 10 | — | Jun 20 – Jul 11 |
| Okra | Mar 29 – Apr 12 | May 31 – Jun 14 | May 31 – Jun 14 | — |
| Basil | Mar 29 – Apr 12 | May 17 – May 31 | — | — |
| Peas | — | — | Mar 29 – Apr 19 | Jul 4 – Jul 25 |
| Spinach | — | — | Mar 29 – Apr 19 | Aug 1 – Aug 22 |
| Radishes | — | — | Apr 5 – May 17 | Aug 15 – Sep 5 |
| Cucumbers | Apr 12 – Apr 19 | May 24 – May 31 | May 17 – May 31 | Jul 11 – Jul 25 |
| Zucchini & Summer Squash | Apr 12 – Apr 19 | — | May 17 – May 31 | Jul 18 – Aug 1 |
| Winter Squash & Pumpkins | Apr 12 – Apr 19 | — | May 17 – May 31 | — |
| Melons & Watermelon | Apr 12 – Apr 19 | May 24 – Jun 7 | — | — |
| Carrots | — | — | Apr 19 – May 17 | Jul 4 – Jul 18 |
| Beets | — | — | Apr 19 – May 17 | Jul 18 – Aug 1 |
| Potatoes | — | — | Apr 19 – May 10 | — |
| Swiss Chard | — | — | Apr 26 – May 24 | Jul 18 – Aug 1 |
| Cilantro | — | — | Apr 26 – May 17 | Aug 1 – Aug 22 |
| Green Beans | — | — | May 17 – Jun 7 | Jul 11 – Jul 25 |
| Sweet Corn | — | — | May 17 – May 31 | — |
| Sweet Potatoes | — | May 24 – Jun 14 | — | — |
| Garlic | — | — | — | Sep 12 – Oct 17 |
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 Spokane Wfo, WA weather station, 26 km away (elevation 2,392 ft (729 m)).
Frost dates near Tumtum
- Ford May 22 · Sep 14
- Springdale May 22 · Sep 14
- Nine Mile Falls May 10 · Sep 26
- Wellpinit Jun 6 · Sep 11
- Clayton May 22 · Sep 14
- Deer Park May 22 · Sep 14
- Loon Lake May 22 · Sep 14
- Reardan May 10 · Sep 26
- Valley May 16 · Sep 15
- Colbert May 22 · Sep 14
Frequently asked questions
When is the last frost in Tumtum, WA?
The median last spring frost in Tumtum, WA is May 10. There is still about a 10% chance of frost after May 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Tumtum, WA?
The median first fall frost is September 26, with about a 10% chance of frost before September 11.
How long is the growing season in Tumtum, WA?
About 139 days between the median last spring frost and first fall frost.
What planting zone is Tumtum, WA?
Tumtum, WA is in USDA hardiness zone 6b.