Bonanza, UT frost dates
Last spring frostMay 12median date
First fall frostOct 5median date
Growing season146 daysfrost-free
Hardiness zone6aZone 6a
How Bonanza compares
- In 8 years out of 10, the last spring frost in Bonanza falls between April 28 and June 1, a 34-day window. The first fall frost falls between September 23 and October 19.
- The median last frost is 2 days later than the Utah median of May 10.
- Its 146-day growing season is longer than 46% of the 250 Utah places with a regular frost season (state median 148 days).
- The last frost is 13 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 164 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 28 |
| 50% (median) | May 12 |
| 10% (safe for tender plants) | June 1 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 23 |
| 50% (median) | October 5 |
| 90% (late) | October 19 |
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 Bonanza, UT
Bonanza, UT frost dates — last frost May 12, first frost Oct 5, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Feb 17 to Mar 3Transplant outside: Apr 14 to Apr 28
Start indoors: Mar 3 to Mar 17Transplant outside: May 26 to Jun 9
Start indoors: Mar 3 to Mar 17Transplant outside: May 26 to Jun 9
Start indoors: Mar 17 to Mar 31Transplant outside: May 19 to Jun 2
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 21 to May 5Sow outdoors: Apr 14 to May 19Plant for fall: Aug 10 to Sep 7
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 14 to Apr 28Sow outdoors: Apr 14 to Apr 28Plant for fall: Jul 27 to Aug 17
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jun 29 to Jul 20
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 21 to May 5Plant for fall: Jun 29 to Jul 20
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jun 29 to Jul 20
Start indoors: Mar 31 to Apr 14Transplant outside: Jun 2 to Jun 16Sow outdoors: Jun 2 to Jun 16
Start indoors: Mar 31 to Apr 14Transplant outside: May 19 to Jun 2
Sow outdoors: Mar 31 to Apr 21Plant for fall: Jul 13 to Aug 3
Sow outdoors: Mar 31 to Apr 21Plant for fall: Aug 10 to Aug 31
Sow outdoors: Apr 7 to May 19Plant for fall: Aug 24 to Sep 14
Start indoors: Apr 14 to Apr 21Transplant outside: May 26 to Jun 2Sow outdoors: May 19 to Jun 2Plant for fall: Jul 20 to Aug 3
Start indoors: Apr 14 to Apr 21Sow outdoors: May 19 to Jun 2Plant for fall: Jul 27 to Aug 10
Start indoors: Apr 14 to Apr 21Sow outdoors: May 19 to Jun 2
Start indoors: Apr 14 to Apr 21Transplant outside: May 26 to Jun 9
Sow outdoors: Apr 21 to May 19Plant for fall: Jul 13 to Jul 27
Sow outdoors: Apr 21 to May 19Plant for fall: Jul 27 to Aug 10
Sow outdoors: Apr 21 to May 12
Sow outdoors: Apr 28 to May 26Plant for fall: Jul 27 to Aug 10
Sow outdoors: Apr 28 to May 19Plant for fall: Aug 10 to Aug 31
Sow outdoors: May 19 to Jun 9Plant for fall: Jul 20 to Aug 3
Sow outdoors: May 19 to Jun 2
Transplant outside: May 26 to Jun 16
Plant for fall: Sep 21 to Oct 26
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Bonanza, UT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 17 – Mar 3 | Apr 14 – Apr 28 | — | — |
| Peppers | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Eggplant | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Tomatoes | Mar 17 – Mar 31 | May 19 – Jun 2 | — | — |
| Lettuce | Mar 17 – Mar 31 | Apr 21 – May 5 | Apr 14 – May 19 | Aug 10 – Sep 7 |
| Kale | Mar 17 – Mar 31 | Apr 14 – Apr 28 | Apr 14 – Apr 28 | Jul 27 – Aug 17 |
| Broccoli | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 29 – Jul 20 |
| Cabbage | Mar 17 – Mar 31 | Apr 21 – May 5 | — | Jun 29 – Jul 20 |
| Cauliflower | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 29 – Jul 20 |
| Okra | Mar 31 – Apr 14 | Jun 2 – Jun 16 | Jun 2 – Jun 16 | — |
| Basil | Mar 31 – Apr 14 | May 19 – Jun 2 | — | — |
| Peas | — | — | Mar 31 – Apr 21 | Jul 13 – Aug 3 |
| Spinach | — | — | Mar 31 – Apr 21 | Aug 10 – Aug 31 |
| Radishes | — | — | Apr 7 – May 19 | Aug 24 – Sep 14 |
| Cucumbers | Apr 14 – Apr 21 | May 26 – Jun 2 | May 19 – Jun 2 | Jul 20 – Aug 3 |
| Zucchini & Summer Squash | Apr 14 – Apr 21 | — | May 19 – Jun 2 | Jul 27 – Aug 10 |
| Winter Squash & Pumpkins | Apr 14 – Apr 21 | — | May 19 – Jun 2 | — |
| Melons & Watermelon | Apr 14 – Apr 21 | May 26 – Jun 9 | — | — |
| Carrots | — | — | Apr 21 – May 19 | Jul 13 – Jul 27 |
| Beets | — | — | Apr 21 – May 19 | Jul 27 – Aug 10 |
| Potatoes | — | — | Apr 21 – May 12 | — |
| Swiss Chard | — | — | Apr 28 – May 26 | Jul 27 – Aug 10 |
| Cilantro | — | — | Apr 28 – May 19 | Aug 10 – Aug 31 |
| Green Beans | — | — | May 19 – Jun 9 | Jul 20 – Aug 3 |
| Sweet Corn | — | — | May 19 – Jun 2 | — |
| Sweet Potatoes | — | May 26 – Jun 16 | — | — |
| Garlic | — | — | — | Sep 21 – Oct 26 |
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 Dinosaur Nm, CO weather station, 30 km away (elevation 5,961 ft (1,817 m)).
Frost dates near Bonanza
- Jensen May 20 · Sep 25
- Randlett May 2 · Oct 3
- Vernal May 7 · Oct 6
- Fort Duchesne May 19 · Oct 2
- Lapoint May 19 · Oct 2
- Tridell May 19 · Oct 2
- Myton May 7 · Oct 5
- Roosevelt May 23 · Sep 22
- Whiterocks May 19 · Sep 29
- Neola May 19 · Sep 29
Frequently asked questions
When is the last frost in Bonanza, UT?
The median last spring frost in Bonanza, UT is May 12. There is still about a 10% chance of frost after June 1, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Bonanza, UT?
The median first fall frost is October 5, with about a 10% chance of frost before September 23.
How long is the growing season in Bonanza, UT?
About 146 days between the median last spring frost and first fall frost.
What planting zone is Bonanza, UT?
Bonanza, UT is in USDA hardiness zone 6a.