Summit, UT frost dates
Last spring frostJun 21median date
First fall frostSep 12median date
Growing season83 daysfrost-free
Hardiness zone6bZone 6b
How Summit compares
- In 8 years out of 10, the last spring frost in Summit falls between June 6 and July 6, a 30-day window. The first fall frost falls between September 1 and September 23.
- The median last frost is 42 days later than the Utah median of May 10.
- Its 83-day growing season is among the shortest of the 250 Utah places with a regular frost season.
- The last frost is 60 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 255 nights a year at or below 32°F.
- Compared with Saint George, UT, 96 km away, the last frost here is 99 days later than there and the growing season is 158 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | June 6 |
| 50% (median) | June 21 |
| 10% (safe for tender plants) | July 6 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 1 |
| 50% (median) | September 12 |
| 90% (late) | September 23 |
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 Summit, UT
Summit, UT frost dates — last frost Jun 21, first frost Sep 12, zone 6b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 29 to Apr 12Transplant outside: May 24 to Jun 7
Start indoors: Apr 12 to Apr 26Transplant outside: Jul 5 to Jul 19
Start indoors: Apr 12 to Apr 26Transplant outside: Jul 5 to Jul 19
Start indoors: Apr 26 to May 10Transplant outside: Jun 28 to Jul 12
Start indoors: Apr 26 to May 10Transplant outside: May 31 to Jun 14Sow outdoors: May 24 to Jun 28Plant for fall: Jul 18 to Aug 15
Start indoors: Apr 26 to May 10Transplant outside: May 24 to Jun 7Sow outdoors: May 24 to Jun 7
Start indoors: Apr 26 to May 10Transplant outside: Jun 7 to Jun 21
Start indoors: Apr 26 to May 10Transplant outside: May 31 to Jun 14
Start indoors: Apr 26 to May 10Transplant outside: Jun 7 to Jun 21
Start indoors: May 10 to May 24Transplant outside: Jul 12 to Jul 26Sow outdoors: Jul 12 to Jul 26
Start indoors: May 10 to May 24Transplant outside: Jun 28 to Jul 12
Sow outdoors: May 10 to May 31
Sow outdoors: May 10 to May 31Plant for fall: Jul 18 to Aug 8
Sow outdoors: May 17 to Jun 28Plant for fall: Aug 1 to Aug 22
Start indoors: May 24 to May 31Transplant outside: Jul 5 to Jul 12Sow outdoors: Jun 28 to Jul 12
Start indoors: May 24 to May 31Sow outdoors: Jun 28 to Jul 12
Start indoors: May 24 to May 31Sow outdoors: Jun 28 to Jul 12
Start indoors: May 24 to May 31Transplant outside: Jul 5 to Jul 19
Sow outdoors: May 31 to Jun 28
Sow outdoors: May 31 to Jun 28
Sow outdoors: May 31 to Jun 21
Sow outdoors: Jun 7 to Jul 5
Sow outdoors: Jun 7 to Jun 28Plant for fall: Jul 18 to Aug 8
Sow outdoors: Jun 28 to Jul 19
Sow outdoors: Jun 28 to Jul 12
Transplant outside: Jul 5 to Jul 26
Plant for fall: Aug 29 to Oct 3
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Summit, UT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 29 – Apr 12 | May 24 – Jun 7 | — | — |
| Peppers Warning: Your frost-free season is about 83 days, which is tight for peppers (75+ days). Choose early varieties and use transplants or row covers. | Apr 12 – Apr 26 | Jul 5 – Jul 19 | — | — |
| Eggplant Warning: Your frost-free season is about 83 days, which is tight for eggplant (75+ days). Choose early varieties and use transplants or row covers. | Apr 12 – Apr 26 | Jul 5 – Jul 19 | — | — |
| Tomatoes Warning: Your frost-free season is about 83 days, which is tight for tomatoes (70+ days). Choose early varieties and use transplants or row covers. | Apr 26 – May 10 | Jun 28 – Jul 12 | — | — |
| Lettuce | Apr 26 – May 10 | May 31 – Jun 14 | May 24 – Jun 28 | Jul 18 – Aug 15 |
| Kale | Apr 26 – May 10 | May 24 – Jun 7 | May 24 – Jun 7 | — |
| Broccoli | Apr 26 – May 10 | Jun 7 – Jun 21 | — | — |
| Cabbage | Apr 26 – May 10 | May 31 – Jun 14 | — | — |
| Cauliflower | Apr 26 – May 10 | Jun 7 – Jun 21 | — | — |
| Okra | May 10 – May 24 | Jul 12 – Jul 26 | Jul 12 – Jul 26 | — |
| Basil | May 10 – May 24 | Jun 28 – Jul 12 | — | — |
| Peas | — | — | May 10 – May 31 | — |
| Spinach | — | — | May 10 – May 31 | Jul 18 – Aug 8 |
| Radishes | — | — | May 17 – Jun 28 | Aug 1 – Aug 22 |
| Cucumbers | May 24 – May 31 | Jul 5 – Jul 12 | Jun 28 – Jul 12 | — |
| Zucchini & Summer Squash | May 24 – May 31 | — | Jun 28 – Jul 12 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 83 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 24 – May 31 | — | Jun 28 – Jul 12 | — |
| Melons & Watermelon Warning: Your frost-free season is about 83 days, which is tight for melons & watermelon (85+ days). Choose early varieties and use transplants or row covers. | May 24 – May 31 | Jul 5 – Jul 19 | — | — |
| Carrots | — | — | May 31 – Jun 28 | — |
| Beets | — | — | May 31 – Jun 28 | — |
| Potatoes | — | — | May 31 – Jun 21 | — |
| Swiss Chard | — | — | Jun 7 – Jul 5 | — |
| Cilantro | — | — | Jun 7 – Jun 28 | Jul 18 – Aug 8 |
| Green Beans | — | — | Jun 28 – Jul 19 | — |
| Sweet Corn Warning: Your frost-free season is about 83 days, which is tight for sweet corn (80+ days). Choose early varieties and use transplants or row covers. | — | — | Jun 28 – Jul 12 | — |
| Sweet Potatoes Warning: Your frost-free season is about 83 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jul 5 – Jul 26 | — | — |
| Garlic | — | — | — | Aug 29 – Oct 3 |
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 Brian Head, UT weather station, 14 km away (elevation 9,770 ft (2,978 m)).
Frost dates near Summit
- Parowan Jun 21 · Sep 12
- Brian Head Jun 21 · Sep 12
- Paragonah Jun 21 · Sep 12
- Cedar City May 4 · Oct 13
- Kanarraville May 9 · Oct 11
- Duck Creek Village Jun 1 · Sep 30
- Panguitch Jun 12 · Sep 12
- Minersville May 10 · Oct 2
- Hatch Jun 19 · Sep 13
- New Harmony May 9 · Oct 11
Frequently asked questions
When is the last frost in Summit, UT?
The median last spring frost in Summit, UT is June 21. There is still about a 10% chance of frost after July 6, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Summit, UT?
The median first fall frost is September 12, with about a 10% chance of frost before September 1.
How long is the growing season in Summit, UT?
About 83 days between the median last spring frost and first fall frost.
What planting zone is Summit, UT?
Summit, UT is in USDA hardiness zone 6b.