Cornish, UT frost dates
Last spring frostMay 17median date
First fall frostSep 18median date
Growing season124 daysfrost-free
Hardiness zone6aZone 6a
How Cornish compares
- In 8 years out of 10, the last spring frost in Cornish falls between May 3 and June 6, a 34-day window. The first fall frost falls between September 1 and October 4.
- The median last frost is 7 days later than the Utah median of May 10.
- Its 124-day growing season is longer than 26% of the 250 Utah places with a regular frost season (state median 148 days).
- The last frost is 18 days later than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 180 nights a year at or below 32°F.
- Compared with Logan, UT, 27 km away, the last frost here is 9 days later than there and the growing season is 23 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 3 |
| 50% (median) | May 17 |
| 10% (safe for tender plants) | June 6 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 1 |
| 50% (median) | September 18 |
| 90% (late) | October 4 |
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 Cornish, UT
Cornish, UT frost dates — last frost May 17, first frost Sep 18, zone 6a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 19 to May 3
Start indoors: Mar 8 to Mar 22Transplant outside: May 31 to Jun 14
Start indoors: Mar 8 to Mar 22Transplant outside: May 31 to Jun 14
Start indoors: Mar 22 to Apr 5Transplant outside: May 24 to Jun 7
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 26 to May 10Sow outdoors: Apr 19 to May 24Plant for fall: Jul 24 to Aug 21
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 19 to May 3Sow outdoors: Apr 19 to May 3Plant for fall: Jul 10 to Jul 31
Start indoors: Mar 22 to Apr 5Transplant outside: May 3 to May 17Plant for fall: Jun 12 to Jul 3
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 26 to May 10Plant for fall: Jun 12 to Jul 3
Start indoors: Mar 22 to Apr 5Transplant outside: May 3 to May 17Plant for fall: Jun 12 to Jul 3
Start indoors: Apr 5 to Apr 19Transplant outside: Jun 7 to Jun 21Sow outdoors: Jun 7 to Jun 21
Start indoors: Apr 5 to Apr 19Transplant outside: May 24 to Jun 7
Sow outdoors: Apr 5 to Apr 26Plant for fall: Jun 26 to Jul 17
Sow outdoors: Apr 5 to Apr 26Plant for fall: Jul 24 to Aug 14
Sow outdoors: Apr 12 to May 24Plant for fall: Aug 7 to Aug 28
Start indoors: Apr 19 to Apr 26Transplant outside: May 31 to Jun 7Sow outdoors: May 24 to Jun 7Plant for fall: Jul 3 to Jul 17
Start indoors: Apr 19 to Apr 26Sow outdoors: May 24 to Jun 7Plant for fall: Jul 10 to Jul 24
Start indoors: Apr 19 to Apr 26Sow outdoors: May 24 to Jun 7
Start indoors: Apr 19 to Apr 26Transplant outside: May 31 to Jun 14
Sow outdoors: Apr 26 to May 24Plant for fall: Jun 26 to Jul 10
Sow outdoors: Apr 26 to May 24Plant for fall: Jul 10 to Jul 24
Sow outdoors: Apr 26 to May 17
Sow outdoors: May 3 to May 31Plant for fall: Jul 10 to Jul 24
Sow outdoors: May 3 to May 24Plant for fall: Jul 24 to Aug 14
Sow outdoors: May 24 to Jun 14Plant for fall: Jul 3 to Jul 17
Sow outdoors: May 24 to Jun 7
Transplant outside: May 31 to Jun 21
Plant for fall: Sep 4 to Oct 9
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Cornish, UT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 22 – Mar 8 | Apr 19 – May 3 | — | — |
| Peppers | Mar 8 – Mar 22 | May 31 – Jun 14 | — | — |
| Eggplant | Mar 8 – Mar 22 | May 31 – Jun 14 | — | — |
| Tomatoes | Mar 22 – Apr 5 | May 24 – Jun 7 | — | — |
| Lettuce | Mar 22 – Apr 5 | Apr 26 – May 10 | Apr 19 – May 24 | Jul 24 – Aug 21 |
| Kale | Mar 22 – Apr 5 | Apr 19 – May 3 | Apr 19 – May 3 | Jul 10 – Jul 31 |
| Broccoli | Mar 22 – Apr 5 | May 3 – May 17 | — | Jun 12 – Jul 3 |
| Cabbage | Mar 22 – Apr 5 | Apr 26 – May 10 | — | Jun 12 – Jul 3 |
| Cauliflower | Mar 22 – Apr 5 | May 3 – May 17 | — | Jun 12 – Jul 3 |
| Okra | Apr 5 – Apr 19 | Jun 7 – Jun 21 | Jun 7 – Jun 21 | — |
| Basil | Apr 5 – Apr 19 | May 24 – Jun 7 | — | — |
| Peas | — | — | Apr 5 – Apr 26 | Jun 26 – Jul 17 |
| Spinach | — | — | Apr 5 – Apr 26 | Jul 24 – Aug 14 |
| Radishes | — | — | Apr 12 – May 24 | Aug 7 – Aug 28 |
| Cucumbers | Apr 19 – Apr 26 | May 31 – Jun 7 | May 24 – Jun 7 | Jul 3 – Jul 17 |
| Zucchini & Summer Squash | Apr 19 – Apr 26 | — | May 24 – Jun 7 | Jul 10 – Jul 24 |
| Winter Squash & Pumpkins | Apr 19 – Apr 26 | — | May 24 – Jun 7 | — |
| Melons & Watermelon | Apr 19 – Apr 26 | May 31 – Jun 14 | — | — |
| Carrots | — | — | Apr 26 – May 24 | Jun 26 – Jul 10 |
| Beets | — | — | Apr 26 – May 24 | Jul 10 – Jul 24 |
| Potatoes | — | — | Apr 26 – May 17 | — |
| Swiss Chard | — | — | May 3 – May 31 | Jul 10 – Jul 24 |
| Cilantro | — | — | May 3 – May 24 | Jul 24 – Aug 14 |
| Green Beans | — | — | May 24 – Jun 14 | Jul 3 – Jul 17 |
| Sweet Corn | — | — | May 24 – Jun 7 | — |
| Sweet Potatoes | — | May 31 – Jun 21 | — | — |
| Garlic | — | — | — | Sep 4 – Oct 9 |
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 Trenton, UT weather station, 6 km away (elevation 4,455 ft (1,358 m)).
Frost dates near Cornish
- Trenton May 17 · Sep 18
- Clarkston May 3 · Oct 12
- Lewiston May 17 · Sep 18
- Newton May 3 · Oct 12
- Richmond May 11 · Oct 5
- Cache Junction May 3 · Oct 12
- Smithfield May 8 · Oct 2
- Plymouth May 3 · Oct 12
- Fielding May 3 · Oct 12
- Collinston May 3 · Oct 12
Frequently asked questions
When is the last frost in Cornish, UT?
The median last spring frost in Cornish, UT is May 17. There is still about a 10% chance of frost after June 6, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Cornish, UT?
The median first fall frost is September 18, with about a 10% chance of frost before September 1.
How long is the growing season in Cornish, UT?
About 124 days between the median last spring frost and first fall frost.
What planting zone is Cornish, UT?
Cornish, UT is in USDA hardiness zone 6a.