Adams, OR frost dates
Last spring frostMay 12median date
First fall frostSep 27median date
Growing season138 daysfrost-free
Hardiness zone7aZone 7a
How Adams compares
- In 8 years out of 10, the last spring frost in Adams falls between April 28 and June 2, a 35-day window. The first fall frost falls between September 8 and October 12.
- The median last frost is 26 days later than the Oregon median of Apr 16.
- Its 138-day growing season is longer than 17% of the 345 Oregon places with a regular frost season (state median 193 days).
- The last frost is 26 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 125 nights a year at or below 32°F.
- Compared with Kennewick, WA, 67 km away, the last frost here is 45 days later than there and the growing season is 78 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 28 |
| 50% (median) | May 12 |
| 10% (safe for tender plants) | June 2 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 8 |
| 50% (median) | September 27 |
| 90% (late) | October 12 |
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 Adams, OR
Adams, OR frost dates — last frost May 12, first frost Sep 27, zone 7a. whenisthelastfrost.com
Crop
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Start indoors: Feb 17 to Mar 3Transplant outside: Apr 14 to Apr 28
Start indoors: Mar 3 to Mar 17Transplant outside: May 26 to Jun 9
Start indoors: Mar 3 to Mar 17Transplant outside: May 26 to Jun 9
Start indoors: Mar 17 to Mar 31Transplant outside: May 19 to Jun 2
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 21 to May 5Sow outdoors: Apr 14 to May 19Plant for fall: Aug 2 to Aug 30
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 14 to Apr 28Sow outdoors: Apr 14 to Apr 28Plant for fall: Jul 19 to Aug 9
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jun 21 to Jul 12
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 21 to May 5Plant for fall: Jun 21 to Jul 12
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jun 21 to Jul 12
Start indoors: Mar 31 to Apr 14Transplant outside: Jun 2 to Jun 16Sow outdoors: Jun 2 to Jun 16
Start indoors: Mar 31 to Apr 14Transplant outside: May 19 to Jun 2
Sow outdoors: Mar 31 to Apr 21Plant for fall: Jul 5 to Jul 26
Sow outdoors: Mar 31 to Apr 21Plant for fall: Aug 2 to Aug 23
Sow outdoors: Apr 7 to May 19Plant for fall: Aug 16 to Sep 6
Start indoors: Apr 14 to Apr 21Transplant outside: May 26 to Jun 2Sow outdoors: May 19 to Jun 2Plant for fall: Jul 12 to Jul 26
Start indoors: Apr 14 to Apr 21Sow outdoors: May 19 to Jun 2Plant for fall: Jul 19 to Aug 2
Start indoors: Apr 14 to Apr 21Sow outdoors: May 19 to Jun 2
Start indoors: Apr 14 to Apr 21Transplant outside: May 26 to Jun 9
Sow outdoors: Apr 21 to May 19Plant for fall: Jul 5 to Jul 19
Sow outdoors: Apr 21 to May 19Plant for fall: Jul 19 to Aug 2
Sow outdoors: Apr 21 to May 12
Sow outdoors: Apr 28 to May 26Plant for fall: Jul 19 to Aug 2
Sow outdoors: Apr 28 to May 19Plant for fall: Aug 2 to Aug 23
Sow outdoors: May 19 to Jun 9Plant for fall: Jul 12 to Jul 26
Sow outdoors: May 19 to Jun 2
Transplant outside: May 26 to Jun 16
Plant for fall: Sep 13 to Oct 18
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Adams, OR
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 17 – Mar 3 | Apr 14 – Apr 28 | — | — |
| Peppers | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Eggplant | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Tomatoes | Mar 17 – Mar 31 | May 19 – Jun 2 | — | — |
| Lettuce | Mar 17 – Mar 31 | Apr 21 – May 5 | Apr 14 – May 19 | Aug 2 – Aug 30 |
| Kale | Mar 17 – Mar 31 | Apr 14 – Apr 28 | Apr 14 – Apr 28 | Jul 19 – Aug 9 |
| Broccoli | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 21 – Jul 12 |
| Cabbage | Mar 17 – Mar 31 | Apr 21 – May 5 | — | Jun 21 – Jul 12 |
| Cauliflower | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 21 – Jul 12 |
| Okra | Mar 31 – Apr 14 | Jun 2 – Jun 16 | Jun 2 – Jun 16 | — |
| Basil | Mar 31 – Apr 14 | May 19 – Jun 2 | — | — |
| Peas | — | — | Mar 31 – Apr 21 | Jul 5 – Jul 26 |
| Spinach | — | — | Mar 31 – Apr 21 | Aug 2 – Aug 23 |
| Radishes | — | — | Apr 7 – May 19 | Aug 16 – Sep 6 |
| Cucumbers | Apr 14 – Apr 21 | May 26 – Jun 2 | May 19 – Jun 2 | Jul 12 – Jul 26 |
| Zucchini & Summer Squash | Apr 14 – Apr 21 | — | May 19 – Jun 2 | Jul 19 – Aug 2 |
| Winter Squash & Pumpkins | Apr 14 – Apr 21 | — | May 19 – Jun 2 | — |
| Melons & Watermelon | Apr 14 – Apr 21 | May 26 – Jun 9 | — | — |
| Carrots | — | — | Apr 21 – May 19 | Jul 5 – Jul 19 |
| Beets | — | — | Apr 21 – May 19 | Jul 19 – Aug 2 |
| Potatoes | — | — | Apr 21 – May 12 | — |
| Swiss Chard | — | — | Apr 28 – May 26 | Jul 19 – Aug 2 |
| Cilantro | — | — | Apr 28 – May 19 | Aug 2 – Aug 23 |
| Green Beans | — | — | May 19 – Jun 9 | Jul 12 – Jul 26 |
| Sweet Corn | — | — | May 19 – Jun 2 | — |
| Sweet Potatoes | — | May 26 – Jun 16 | — | — |
| Garlic | — | — | — | Sep 13 – Oct 18 |
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 Pendleton Branch Exp Stn, OR weather station, 7 km away (elevation 1,486 ft (453 m)).
Frost dates near Adams
- Athena Mar 25 · Oct 29
- Weston Mar 25 · Oct 29
- Helix May 12 · Sep 27
- Pendleton Apr 22 · Oct 9
- Milton Freewater Mar 25 · Oct 29
- Meacham frost any month
- Pilot Rock May 7 · Oct 4
- Echo Apr 26 · Oct 10
- Stanfield Apr 26 · Oct 10
- Summerville May 24 · Sep 18
Frequently asked questions
When is the last frost in Adams, OR?
The median last spring frost in Adams, OR is May 12. There is still about a 10% chance of frost after June 2, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Adams, OR?
The median first fall frost is September 27, with about a 10% chance of frost before September 8.
How long is the growing season in Adams, OR?
About 138 days between the median last spring frost and first fall frost.
What planting zone is Adams, OR?
Adams, OR is in USDA hardiness zone 7a.