Roslyn, WA frost dates
Last spring frostMay 13median date
First fall frostSep 25median date
Growing season135 daysfrost-free
Hardiness zone7aZone 7a
How Roslyn compares
- In 8 years out of 10, the last spring frost in Roslyn falls between April 29 and June 1, a 33-day window. The first fall frost falls between September 11 and October 7.
- The median last frost is 22 days later than the Washington median of Apr 21.
- Its 135-day growing season is longer than 9% of the 491 Washington places with a regular frost season (state median 182 days).
- The last frost is 27 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 156 nights a year at or below 32°F.
- Compared with Yakima, WA, 76 km away, the last frost here is 35 days later than there and the growing season is 63 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 29 |
| 50% (median) | May 13 |
| 10% (safe for tender plants) | June 1 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 11 |
| 50% (median) | September 25 |
| 90% (late) | October 7 |
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 Roslyn, WA
Roslyn, WA frost dates — last frost May 13, first frost Sep 25, zone 7a. whenisthelastfrost.com
Crop
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Start indoors: Feb 18 to Mar 4Transplant outside: Apr 15 to Apr 29
Start indoors: Mar 4 to Mar 18Transplant outside: May 27 to Jun 10
Start indoors: Mar 4 to Mar 18Transplant outside: May 27 to Jun 10
Start indoors: Mar 18 to Apr 1Transplant outside: May 20 to Jun 3
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 22 to May 6Sow outdoors: Apr 15 to May 20Plant for fall: Jul 31 to Aug 28
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 15 to Apr 29Sow outdoors: Apr 15 to Apr 29Plant for fall: Jul 17 to Aug 7
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 29 to May 13Plant for fall: Jun 19 to Jul 10
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 22 to May 6Plant for fall: Jun 19 to Jul 10
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 29 to May 13Plant for fall: Jun 19 to Jul 10
Start indoors: Apr 1 to Apr 15Transplant outside: Jun 3 to Jun 17Sow outdoors: Jun 3 to Jun 17
Start indoors: Apr 1 to Apr 15Transplant outside: May 20 to Jun 3
Sow outdoors: Apr 1 to Apr 22Plant for fall: Jul 3 to Jul 24
Sow outdoors: Apr 1 to Apr 22Plant for fall: Jul 31 to Aug 21
Sow outdoors: Apr 8 to May 20Plant for fall: Aug 14 to Sep 4
Start indoors: Apr 15 to Apr 22Transplant outside: May 27 to Jun 3Sow outdoors: May 20 to Jun 3Plant for fall: Jul 10 to Jul 24
Start indoors: Apr 15 to Apr 22Sow outdoors: May 20 to Jun 3Plant for fall: Jul 17 to Jul 31
Start indoors: Apr 15 to Apr 22Sow outdoors: May 20 to Jun 3
Start indoors: Apr 15 to Apr 22Transplant outside: May 27 to Jun 10
Sow outdoors: Apr 22 to May 20Plant for fall: Jul 3 to Jul 17
Sow outdoors: Apr 22 to May 20Plant for fall: Jul 17 to Jul 31
Sow outdoors: Apr 22 to May 13
Sow outdoors: Apr 29 to May 27Plant for fall: Jul 17 to Jul 31
Sow outdoors: Apr 29 to May 20Plant for fall: Jul 31 to Aug 21
Sow outdoors: May 20 to Jun 10Plant for fall: Jul 10 to Jul 24
Sow outdoors: May 20 to Jun 3
Transplant outside: May 27 to Jun 17
Plant for fall: Sep 11 to Oct 16
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Roslyn, WA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 18 – Mar 4 | Apr 15 – Apr 29 | — | — |
| Peppers | Mar 4 – Mar 18 | May 27 – Jun 10 | — | — |
| Eggplant | Mar 4 – Mar 18 | May 27 – Jun 10 | — | — |
| Tomatoes | Mar 18 – Apr 1 | May 20 – Jun 3 | — | — |
| Lettuce | Mar 18 – Apr 1 | Apr 22 – May 6 | Apr 15 – May 20 | Jul 31 – Aug 28 |
| Kale | Mar 18 – Apr 1 | Apr 15 – Apr 29 | Apr 15 – Apr 29 | Jul 17 – Aug 7 |
| Broccoli | Mar 18 – Apr 1 | Apr 29 – May 13 | — | Jun 19 – Jul 10 |
| Cabbage | Mar 18 – Apr 1 | Apr 22 – May 6 | — | Jun 19 – Jul 10 |
| Cauliflower | Mar 18 – Apr 1 | Apr 29 – May 13 | — | Jun 19 – Jul 10 |
| Okra | Apr 1 – Apr 15 | Jun 3 – Jun 17 | Jun 3 – Jun 17 | — |
| Basil | Apr 1 – Apr 15 | May 20 – Jun 3 | — | — |
| Peas | — | — | Apr 1 – Apr 22 | Jul 3 – Jul 24 |
| Spinach | — | — | Apr 1 – Apr 22 | Jul 31 – Aug 21 |
| Radishes | — | — | Apr 8 – May 20 | Aug 14 – Sep 4 |
| Cucumbers | Apr 15 – Apr 22 | May 27 – Jun 3 | May 20 – Jun 3 | Jul 10 – Jul 24 |
| Zucchini & Summer Squash | Apr 15 – Apr 22 | — | May 20 – Jun 3 | Jul 17 – Jul 31 |
| Winter Squash & Pumpkins | Apr 15 – Apr 22 | — | May 20 – Jun 3 | — |
| Melons & Watermelon | Apr 15 – Apr 22 | May 27 – Jun 10 | — | — |
| Carrots | — | — | Apr 22 – May 20 | Jul 3 – Jul 17 |
| Beets | — | — | Apr 22 – May 20 | Jul 17 – Jul 31 |
| Potatoes | — | — | Apr 22 – May 13 | — |
| Swiss Chard | — | — | Apr 29 – May 27 | Jul 17 – Jul 31 |
| Cilantro | — | — | Apr 29 – May 20 | Jul 31 – Aug 21 |
| Green Beans | — | — | May 20 – Jun 10 | Jul 10 – Jul 24 |
| Sweet Corn | — | — | May 20 – Jun 3 | — |
| Sweet Potatoes | — | May 27 – Jun 17 | — | — |
| Garlic | — | — | — | Sep 11 – Oct 16 |
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 Cle Elum, WA weather station, 8 km away (elevation 1,900 ft (579 m)).
Frost dates near Roslyn
- Cle Elum May 13 · Sep 25
- Ronald May 9 · Oct 6
- South Cle Elum May 13 · Sep 25
- Easton May 9 · Oct 6
- Thorp Apr 28 · Oct 7
- Snoqualmie Pass May 14 · Oct 17
- Ellensburg May 8 · Oct 2
- Naches May 8 · Oct 2
- Peshastin May 10 · Sep 30
- Dryden May 10 · Sep 30
Frequently asked questions
When is the last frost in Roslyn, WA?
The median last spring frost in Roslyn, WA is May 13. There is still about a 10% chance of frost after June 1, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Roslyn, WA?
The median first fall frost is September 25, with about a 10% chance of frost before September 11.
How long is the growing season in Roslyn, WA?
About 135 days between the median last spring frost and first fall frost.
What planting zone is Roslyn, WA?
Roslyn, WA is in USDA hardiness zone 7a.