Arock, OR frost dates
How Arock compares
- In 8 years out of 10, the last spring frost in Arock falls between May 20 and July 3, a 44-day window. The first fall frost falls between August 27 and September 24.
- The median last frost is 56 days later than the Oregon median of Apr 16.
- Its 91-day growing season is among the shortest of the 345 Oregon places with a regular frost season.
- The last frost is 50 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 182 nights a year at or below 32°F.
- Compared with Caldwell, ID, 103 km away, the last frost here is 49 days later than there and the growing season is 87 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 20 |
| 50% (median) | June 11 |
| 10% (safe for tender plants) | July 3 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 27 |
| 50% (median) | September 10 |
| 90% (late) | September 24 |
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 Arock, OR
Arock, OR frost dates — last frost Jun 11, first frost Sep 10, zone 6b. whenisthelastfrost.com
When to plant vegetables in Arock, OR
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 19 – Apr 2 | May 14 – May 28 | — | — |
| Peppers | Apr 2 – Apr 16 | Jun 25 – Jul 9 | — | — |
| Eggplant | Apr 2 – Apr 16 | Jun 25 – Jul 9 | — | — |
| Tomatoes | Apr 16 – Apr 30 | Jun 18 – Jul 2 | — | — |
| Lettuce | Apr 16 – Apr 30 | May 21 – Jun 4 | May 14 – Jun 18 | Jul 16 – Aug 13 |
| Kale | Apr 16 – Apr 30 | May 14 – May 28 | May 14 – May 28 | Jul 2 – Jul 23 |
| Broccoli | Apr 16 – Apr 30 | May 28 – Jun 11 | — | — |
| Cabbage | Apr 16 – Apr 30 | May 21 – Jun 4 | — | — |
| Cauliflower | Apr 16 – Apr 30 | May 28 – Jun 11 | — | — |
| Okra | Apr 30 – May 14 | Jul 2 – Jul 16 | Jul 2 – Jul 16 | — |
| Basil | Apr 30 – May 14 | Jun 18 – Jul 2 | — | — |
| Peas | — | — | Apr 30 – May 21 | — |
| Spinach | — | — | Apr 30 – May 21 | Jul 16 – Aug 6 |
| Radishes | — | — | May 7 – Jun 18 | Jul 30 – Aug 20 |
| Cucumbers | May 14 – May 21 | Jun 25 – Jul 2 | Jun 18 – Jul 2 | — |
| Zucchini & Summer Squash | May 14 – May 21 | — | Jun 18 – Jul 2 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 91 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 14 – May 21 | — | Jun 18 – Jul 2 | — |
| Melons & Watermelon Warning: Your frost-free season is about 91 days, which is tight for melons & watermelon (85+ days). Choose early varieties and use transplants or row covers. | May 14 – May 21 | Jun 25 – Jul 9 | — | — |
| Carrots | — | — | May 21 – Jun 18 | — |
| Beets | — | — | May 21 – Jun 18 | — |
| Potatoes | — | — | May 21 – Jun 11 | — |
| Swiss Chard | — | — | May 28 – Jun 25 | — |
| Cilantro | — | — | May 28 – Jun 18 | Jul 16 – Aug 6 |
| Green Beans | — | — | Jun 18 – Jul 9 | — |
| Sweet Corn Warning: Your frost-free season is about 91 days, which is tight for sweet corn (80+ days). Choose early varieties and use transplants or row covers. | — | — | Jun 18 – Jul 2 | — |
| Sweet Potatoes Warning: Your frost-free season is about 91 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 25 – Jul 16 | — | — |
| Garlic | — | — | — | Aug 27 – Oct 1 |
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 Rome 2 Nw, OR weather station, 14 km away (elevation 3,406 ft (1,038 m)).
Frost dates near Arock
- Jordan Valley Jun 11 · Sep 10
- Riverside Jun 7 · Sep 6
- Adrian Apr 24 · Oct 9
- Crane Jun 7 · Sep 6
- Diamond May 29 · Sep 18
- Harper May 7 · Oct 3
- Nyssa Apr 18 · Oct 18
- Juntura Jun 5 · Sep 5
- Fields May 10 · Oct 7
- Westfall May 7 · Oct 3
Frequently asked questions
When is the last frost in Arock, OR?
The median last spring frost in Arock, OR is June 11. There is still about a 10% chance of frost after July 3, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Arock, OR?
The median first fall frost is September 10, with about a 10% chance of frost before August 27.
How long is the growing season in Arock, OR?
About 91 days between the median last spring frost and first fall frost.
What planting zone is Arock, OR?
Arock, OR is in USDA hardiness zone 6b.