Grantsville, UT frost dates
Last spring frostMay 2median date
First fall frostOct 14median date
Growing season165 daysfrost-free
Hardiness zone7aZone 7a
How Grantsville compares
- In 8 years out of 10, the last spring frost in Grantsville falls between April 17 and May 19, a 32-day window. The first fall frost falls between September 30 and October 27.
- The median last frost is 8 days earlier than the Utah median of May 10.
- Its 165-day growing season is longer than 70% of the 250 Utah places with a regular frost season (state median 148 days).
- The last frost is 16 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 142 nights a year at or below 32°F.
- Compared with West Jordan, UT, 40 km away, the last frost here is 14 days later than there and the growing season is 22 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 17 |
| 50% (median) | May 2 |
| 10% (safe for tender plants) | May 19 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 30 |
| 50% (median) | October 14 |
| 90% (late) | October 27 |
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 Grantsville, UT
Grantsville, UT frost dates — last frost May 2, first frost Oct 14, zone 7a. whenisthelastfrost.com
Crop
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Start indoors: Feb 7 to Feb 21Transplant outside: Apr 4 to Apr 18
Start indoors: Feb 21 to Mar 7Transplant outside: May 16 to May 30
Start indoors: Feb 21 to Mar 7Transplant outside: May 16 to May 30
Start indoors: Mar 7 to Mar 21Transplant outside: May 9 to May 23
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 11 to Apr 25Sow outdoors: Apr 4 to May 9Plant for fall: Aug 19 to Sep 16
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 4 to Apr 18Sow outdoors: Apr 4 to Apr 18Plant for fall: Aug 5 to Aug 26
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 18 to May 2Plant for fall: Jul 8 to Jul 29
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 11 to Apr 25Plant for fall: Jul 8 to Jul 29
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 18 to May 2Plant for fall: Jul 8 to Jul 29
Start indoors: Mar 21 to Apr 4Transplant outside: May 23 to Jun 6Sow outdoors: May 23 to Jun 6
Start indoors: Mar 21 to Apr 4Transplant outside: May 9 to May 23
Sow outdoors: Mar 21 to Apr 11Plant for fall: Jul 22 to Aug 12
Sow outdoors: Mar 21 to Apr 11Plant for fall: Aug 19 to Sep 9
Sow outdoors: Mar 28 to May 9Plant for fall: Sep 2 to Sep 23
Start indoors: Apr 4 to Apr 11Transplant outside: May 16 to May 23Sow outdoors: May 9 to May 23Plant for fall: Jul 29 to Aug 12
Start indoors: Apr 4 to Apr 11Sow outdoors: May 9 to May 23Plant for fall: Aug 5 to Aug 19
Start indoors: Apr 4 to Apr 11Sow outdoors: May 9 to May 23
Start indoors: Apr 4 to Apr 11Transplant outside: May 16 to May 30
Sow outdoors: Apr 11 to May 9Plant for fall: Jul 22 to Aug 5
Sow outdoors: Apr 11 to May 9Plant for fall: Aug 5 to Aug 19
Sow outdoors: Apr 11 to May 2
Sow outdoors: Apr 18 to May 16Plant for fall: Aug 5 to Aug 19
Sow outdoors: Apr 18 to May 9Plant for fall: Aug 19 to Sep 9
Sow outdoors: May 9 to May 30Plant for fall: Jul 29 to Aug 12
Sow outdoors: May 9 to May 23
Transplant outside: May 16 to Jun 6
Plant for fall: Sep 30 to Nov 4
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Grantsville, UT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 7 – Feb 21 | Apr 4 – Apr 18 | — | — |
| Peppers | Feb 21 – Mar 7 | May 16 – May 30 | — | — |
| Eggplant | Feb 21 – Mar 7 | May 16 – May 30 | — | — |
| Tomatoes | Mar 7 – Mar 21 | May 9 – May 23 | — | — |
| Lettuce | Mar 7 – Mar 21 | Apr 11 – Apr 25 | Apr 4 – May 9 | Aug 19 – Sep 16 |
| Kale | Mar 7 – Mar 21 | Apr 4 – Apr 18 | Apr 4 – Apr 18 | Aug 5 – Aug 26 |
| Broccoli | Mar 7 – Mar 21 | Apr 18 – May 2 | — | Jul 8 – Jul 29 |
| Cabbage | Mar 7 – Mar 21 | Apr 11 – Apr 25 | — | Jul 8 – Jul 29 |
| Cauliflower | Mar 7 – Mar 21 | Apr 18 – May 2 | — | Jul 8 – Jul 29 |
| Okra | Mar 21 – Apr 4 | May 23 – Jun 6 | May 23 – Jun 6 | — |
| Basil | Mar 21 – Apr 4 | May 9 – May 23 | — | — |
| Peas | — | — | Mar 21 – Apr 11 | Jul 22 – Aug 12 |
| Spinach | — | — | Mar 21 – Apr 11 | Aug 19 – Sep 9 |
| Radishes | — | — | Mar 28 – May 9 | Sep 2 – Sep 23 |
| Cucumbers | Apr 4 – Apr 11 | May 16 – May 23 | May 9 – May 23 | Jul 29 – Aug 12 |
| Zucchini & Summer Squash | Apr 4 – Apr 11 | — | May 9 – May 23 | Aug 5 – Aug 19 |
| Winter Squash & Pumpkins | Apr 4 – Apr 11 | — | May 9 – May 23 | — |
| Melons & Watermelon | Apr 4 – Apr 11 | May 16 – May 30 | — | — |
| Carrots | — | — | Apr 11 – May 9 | Jul 22 – Aug 5 |
| Beets | — | — | Apr 11 – May 9 | Aug 5 – Aug 19 |
| Potatoes | — | — | Apr 11 – May 2 | — |
| Swiss Chard | — | — | Apr 18 – May 16 | Aug 5 – Aug 19 |
| Cilantro | — | — | Apr 18 – May 9 | Aug 19 – Sep 9 |
| Green Beans | — | — | May 9 – May 30 | Jul 29 – Aug 12 |
| Sweet Corn | — | — | May 9 – May 23 | — |
| Sweet Potatoes | — | May 16 – Jun 6 | — | — |
| Garlic | — | — | — | Sep 30 – Nov 4 |
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 Grantsville 2w, UT weather station, 4 km away (elevation 4,551 ft (1,387 m)).
Frost dates near Grantsville
- Tooele May 2 · Oct 16
- Stockton May 2 · Oct 16
- Rush Valley May 15 · Oct 5
- Bingham Canyon Apr 18 · Oct 22
- Magna Apr 3 · Nov 4
- Herriman Apr 18 · Oct 22
- West Jordan Apr 18 · Oct 22
- West Valley City Apr 8 · Oct 31
- Dugway May 15 · Oct 5
- South Jordan Apr 18 · Oct 22
Frequently asked questions
When is the last frost in Grantsville, UT?
The median last spring frost in Grantsville, UT is May 2. There is still about a 10% chance of frost after May 19, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Grantsville, UT?
The median first fall frost is October 14, with about a 10% chance of frost before September 30.
How long is the growing season in Grantsville, UT?
About 165 days between the median last spring frost and first fall frost.
What planting zone is Grantsville, UT?
Grantsville, UT is in USDA hardiness zone 7a.