Prineville, OR frost dates
Last spring frostJun 1median date
First fall frostSep 22median date
Growing season113 daysfrost-free
Hardiness zone6bZone 6b
How Prineville compares
- In 8 years out of 10, the last spring frost in Prineville falls between May 8 and June 22, a 45-day window. The first fall frost falls between August 31 and October 9.
- The median last frost is 46 days later than the Oregon median of Apr 16.
- Its 113-day growing season is longer than 9% of the 345 Oregon places with a regular frost season (state median 193 days).
- The last frost is 40 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 166 nights a year at or below 32°F.
- Compared with Bend, OR, 47 km away, the last frost here is 5 days earlier than there and the growing season is 7 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 8 |
| 50% (median) | June 1 |
| 10% (safe for tender plants) | June 22 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 31 |
| 50% (median) | September 22 |
| 90% (late) | October 9 |
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 Prineville, OR
Prineville, OR frost dates — last frost Jun 1, first frost Sep 22, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Mar 9 to Mar 23Transplant outside: May 4 to May 18
Start indoors: Mar 23 to Apr 6Transplant outside: Jun 15 to Jun 29
Start indoors: Mar 23 to Apr 6Transplant outside: Jun 15 to Jun 29
Start indoors: Apr 6 to Apr 20Transplant outside: Jun 8 to Jun 22
Start indoors: Apr 6 to Apr 20Transplant outside: May 11 to May 25Sow outdoors: May 4 to Jun 8Plant for fall: Jul 28 to Aug 25
Start indoors: Apr 6 to Apr 20Transplant outside: May 4 to May 18Sow outdoors: May 4 to May 18Plant for fall: Jul 14 to Aug 4
Start indoors: Apr 6 to Apr 20Transplant outside: May 18 to Jun 1Plant for fall: Jun 16 to Jul 7
Start indoors: Apr 6 to Apr 20Transplant outside: May 11 to May 25Plant for fall: Jun 16 to Jul 7
Start indoors: Apr 6 to Apr 20Transplant outside: May 18 to Jun 1Plant for fall: Jun 16 to Jul 7
Start indoors: Apr 20 to May 4Transplant outside: Jun 22 to Jul 6Sow outdoors: Jun 22 to Jul 6
Start indoors: Apr 20 to May 4Transplant outside: Jun 8 to Jun 22
Sow outdoors: Apr 20 to May 11Plant for fall: Jun 30 to Jul 21
Sow outdoors: Apr 20 to May 11Plant for fall: Jul 28 to Aug 18
Sow outdoors: Apr 27 to Jun 8Plant for fall: Aug 11 to Sep 1
Start indoors: May 4 to May 11Transplant outside: Jun 15 to Jun 22Sow outdoors: Jun 8 to Jun 22Plant for fall: Jul 7 to Jul 21
Start indoors: May 4 to May 11Sow outdoors: Jun 8 to Jun 22Plant for fall: Jul 14 to Jul 28
Start indoors: May 4 to May 11Sow outdoors: Jun 8 to Jun 22
Start indoors: May 4 to May 11Transplant outside: Jun 15 to Jun 29
Sow outdoors: May 11 to Jun 8Plant for fall: Jun 30 to Jul 14
Sow outdoors: May 11 to Jun 8Plant for fall: Jul 14 to Jul 28
Sow outdoors: May 11 to Jun 1
Sow outdoors: May 18 to Jun 15Plant for fall: Jul 14 to Jul 28
Sow outdoors: May 18 to Jun 8Plant for fall: Jul 28 to Aug 18
Sow outdoors: Jun 8 to Jun 29
Sow outdoors: Jun 8 to Jun 22
Transplant outside: Jun 15 to Jul 6
Plant for fall: Sep 8 to Oct 13
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Prineville, OR
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 9 – Mar 23 | May 4 – May 18 | — | — |
| Peppers | Mar 23 – Apr 6 | Jun 15 – Jun 29 | — | — |
| Eggplant | Mar 23 – Apr 6 | Jun 15 – Jun 29 | — | — |
| Tomatoes | Apr 6 – Apr 20 | Jun 8 – Jun 22 | — | — |
| Lettuce | Apr 6 – Apr 20 | May 11 – May 25 | May 4 – Jun 8 | Jul 28 – Aug 25 |
| Kale | Apr 6 – Apr 20 | May 4 – May 18 | May 4 – May 18 | Jul 14 – Aug 4 |
| Broccoli | Apr 6 – Apr 20 | May 18 – Jun 1 | — | Jun 16 – Jul 7 |
| Cabbage | Apr 6 – Apr 20 | May 11 – May 25 | — | Jun 16 – Jul 7 |
| Cauliflower | Apr 6 – Apr 20 | May 18 – Jun 1 | — | Jun 16 – Jul 7 |
| Okra | Apr 20 – May 4 | Jun 22 – Jul 6 | Jun 22 – Jul 6 | — |
| Basil | Apr 20 – May 4 | Jun 8 – Jun 22 | — | — |
| Peas | — | — | Apr 20 – May 11 | Jun 30 – Jul 21 |
| Spinach | — | — | Apr 20 – May 11 | Jul 28 – Aug 18 |
| Radishes | — | — | Apr 27 – Jun 8 | Aug 11 – Sep 1 |
| Cucumbers | May 4 – May 11 | Jun 15 – Jun 22 | Jun 8 – Jun 22 | Jul 7 – Jul 21 |
| Zucchini & Summer Squash | May 4 – May 11 | — | Jun 8 – Jun 22 | Jul 14 – Jul 28 |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 113 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 4 – May 11 | — | Jun 8 – Jun 22 | — |
| Melons & Watermelon | May 4 – May 11 | Jun 15 – Jun 29 | — | — |
| Carrots | — | — | May 11 – Jun 8 | Jun 30 – Jul 14 |
| Beets | — | — | May 11 – Jun 8 | Jul 14 – Jul 28 |
| Potatoes | — | — | May 11 – Jun 1 | — |
| Swiss Chard | — | — | May 18 – Jun 15 | Jul 14 – Jul 28 |
| Cilantro | — | — | May 18 – Jun 8 | Jul 28 – Aug 18 |
| Green Beans | — | — | Jun 8 – Jun 29 | — |
| Sweet Corn | — | — | Jun 8 – Jun 22 | — |
| Sweet Potatoes Warning: Your frost-free season is about 113 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 15 – Jul 6 | — | — |
| Garlic | — | — | — | Sep 8 – Oct 13 |
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 Prineville, OR weather station, about 1 km away (elevation 2,877 ft (877 m)).
Frost dates near Prineville
- Powell Butte Jun 9 · Sep 14
- Redmond Jun 9 · Sep 14
- Terrebonne Jun 9 · Sep 14
- Culver May 19 · Oct 4
- Madras May 19 · Oct 4
- Ashwood May 22 · Oct 3
- Bend Jun 6 · Sep 20
- Post Jun 2 · Sep 17
- Sisters frost any month
- Warm Springs May 5 · Oct 7
Frequently asked questions
When is the last frost in Prineville, OR?
The median last spring frost in Prineville, OR is June 1. There is still about a 10% chance of frost after June 22, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Prineville, OR?
The median first fall frost is September 22, with about a 10% chance of frost before August 31.
How long is the growing season in Prineville, OR?
About 113 days between the median last spring frost and first fall frost.
What planting zone is Prineville, OR?
Prineville, OR is in USDA hardiness zone 6b.