Prospect, OR frost dates
Last spring frostMay 19median date
First fall frostOct 3median date
Growing season137 daysfrost-free
Hardiness zone8aZone 8a
How Prospect compares
- In 8 years out of 10, the last spring frost in Prospect falls between April 29 and June 9, a 41-day window. The first fall frost falls between September 13 and October 20.
- The median last frost is 33 days later than the Oregon median of Apr 16.
- Its 137-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 51 days later than the zone 8a median of Mar 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 8a chart.
- The weather station records an average of 116 nights a year at or below 32°F.
- Compared with Medford, OR, 58 km away, the last frost here is 41 days later than there and the growing season is 67 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 29 |
| 50% (median) | May 19 |
| 10% (safe for tender plants) | June 9 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 13 |
| 50% (median) | October 3 |
| 90% (late) | October 20 |
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 Prospect, OR
Prospect, OR frost dates — last frost May 19, first frost Oct 3, zone 8a. whenisthelastfrost.com
Crop
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Start indoors: Feb 24 to Mar 10Transplant outside: Apr 21 to May 5
Start indoors: Mar 10 to Mar 24Transplant outside: Jun 2 to Jun 16
Start indoors: Mar 10 to Mar 24Transplant outside: Jun 2 to Jun 16
Start indoors: Mar 24 to Apr 7Transplant outside: May 26 to Jun 9
Start indoors: Mar 24 to Apr 7Transplant outside: Apr 28 to May 12Sow outdoors: Apr 21 to May 26Plant for fall: Aug 8 to Sep 5
Start indoors: Mar 24 to Apr 7Transplant outside: Apr 21 to May 5Sow outdoors: Apr 21 to May 5Plant for fall: Jul 25 to Aug 15
Start indoors: Mar 24 to Apr 7Transplant outside: May 5 to May 19Plant for fall: Jun 27 to Jul 18
Start indoors: Mar 24 to Apr 7Transplant outside: Apr 28 to May 12Plant for fall: Jun 27 to Jul 18
Start indoors: Mar 24 to Apr 7Transplant outside: May 5 to May 19Plant for fall: Jun 27 to Jul 18
Start indoors: Apr 7 to Apr 21Transplant outside: Jun 9 to Jun 23Sow outdoors: Jun 9 to Jun 23
Start indoors: Apr 7 to Apr 21Transplant outside: May 26 to Jun 9
Sow outdoors: Apr 7 to Apr 28Plant for fall: Jul 11 to Aug 1
Sow outdoors: Apr 7 to Apr 28Plant for fall: Aug 8 to Aug 29
Sow outdoors: Apr 14 to May 26Plant for fall: Aug 22 to Sep 12
Start indoors: Apr 21 to Apr 28Transplant outside: Jun 2 to Jun 9Sow outdoors: May 26 to Jun 9Plant for fall: Jul 18 to Aug 1
Start indoors: Apr 21 to Apr 28Sow outdoors: May 26 to Jun 9Plant for fall: Jul 25 to Aug 8
Start indoors: Apr 21 to Apr 28Sow outdoors: May 26 to Jun 9
Start indoors: Apr 21 to Apr 28Transplant outside: Jun 2 to Jun 16
Sow outdoors: Apr 28 to May 26Plant for fall: Jul 11 to Jul 25
Sow outdoors: Apr 28 to May 26Plant for fall: Jul 25 to Aug 8
Sow outdoors: Apr 28 to May 19
Sow outdoors: May 5 to Jun 2Plant for fall: Jul 25 to Aug 8
Sow outdoors: May 5 to May 26Plant for fall: Aug 8 to Aug 29
Sow outdoors: May 26 to Jun 16Plant for fall: Jul 18 to Aug 1
Sow outdoors: May 26 to Jun 9
Transplant outside: Jun 2 to Jun 23
Plant for fall: Sep 19 to Oct 24
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Prospect, OR
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 24 – Mar 10 | Apr 21 – May 5 | — | — |
| Peppers | Mar 10 – Mar 24 | Jun 2 – Jun 16 | — | — |
| Eggplant | Mar 10 – Mar 24 | Jun 2 – Jun 16 | — | — |
| Tomatoes | Mar 24 – Apr 7 | May 26 – Jun 9 | — | — |
| Lettuce | Mar 24 – Apr 7 | Apr 28 – May 12 | Apr 21 – May 26 | Aug 8 – Sep 5 |
| Kale | Mar 24 – Apr 7 | Apr 21 – May 5 | Apr 21 – May 5 | Jul 25 – Aug 15 |
| Broccoli | Mar 24 – Apr 7 | May 5 – May 19 | — | Jun 27 – Jul 18 |
| Cabbage | Mar 24 – Apr 7 | Apr 28 – May 12 | — | Jun 27 – Jul 18 |
| Cauliflower | Mar 24 – Apr 7 | May 5 – May 19 | — | Jun 27 – Jul 18 |
| Okra | Apr 7 – Apr 21 | Jun 9 – Jun 23 | Jun 9 – Jun 23 | — |
| Basil | Apr 7 – Apr 21 | May 26 – Jun 9 | — | — |
| Peas | — | — | Apr 7 – Apr 28 | Jul 11 – Aug 1 |
| Spinach | — | — | Apr 7 – Apr 28 | Aug 8 – Aug 29 |
| Radishes | — | — | Apr 14 – May 26 | Aug 22 – Sep 12 |
| Cucumbers | Apr 21 – Apr 28 | Jun 2 – Jun 9 | May 26 – Jun 9 | Jul 18 – Aug 1 |
| Zucchini & Summer Squash | Apr 21 – Apr 28 | — | May 26 – Jun 9 | Jul 25 – Aug 8 |
| Winter Squash & Pumpkins | Apr 21 – Apr 28 | — | May 26 – Jun 9 | — |
| Melons & Watermelon | Apr 21 – Apr 28 | Jun 2 – Jun 16 | — | — |
| Carrots | — | — | Apr 28 – May 26 | Jul 11 – Jul 25 |
| Beets | — | — | Apr 28 – May 26 | Jul 25 – Aug 8 |
| Potatoes | — | — | Apr 28 – May 19 | — |
| Swiss Chard | — | — | May 5 – Jun 2 | Jul 25 – Aug 8 |
| Cilantro | — | — | May 5 – May 26 | Aug 8 – Aug 29 |
| Green Beans | — | — | May 26 – Jun 16 | Jul 18 – Aug 1 |
| Sweet Corn | — | — | May 26 – Jun 9 | — |
| Sweet Potatoes | — | Jun 2 – Jun 23 | — | — |
| Garlic | — | — | — | Sep 19 – Oct 24 |
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 Prospect 2 Sw, OR weather station, 2 km away (elevation 2,484 ft (757 m)).
Frost dates near Prospect
- Butte Falls Apr 29 · Oct 17
- Trail Apr 29 · Oct 17
- Shady Cove Apr 29 · Oct 17
- Crater Lake frost any month
- Tiller Apr 29 · Oct 17
- Eagle Point Apr 8 · Oct 29
- Fort Klamath frost any month
- White City Apr 8 · Oct 29
- Central Point Apr 8 · Oct 29
- Azalea Mar 31 · Nov 6
Frequently asked questions
When is the last frost in Prospect, OR?
The median last spring frost in Prospect, OR is May 19. There is still about a 10% chance of frost after June 9, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Prospect, OR?
The median first fall frost is October 3, with about a 10% chance of frost before September 13.
How long is the growing season in Prospect, OR?
About 137 days between the median last spring frost and first fall frost.
What planting zone is Prospect, OR?
Prospect, OR is in USDA hardiness zone 8a.