Frost dates for ZIP 84308 (Cornish, UT)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Trenton, UT (5 miles away).
- Average last spring frostMay 1750% chance of a 32°F freeze after this date
- Average first fall frostSep 1850% chance of a 32°F freeze by this date
- Growing season (frost-free)121 daysmedian, 32°F threshold
- USDA hardiness zone6a-10 to -5°F avg. coldest night
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This week in your yard
As of Oct 17, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
50°F 50–55°F
24-hour average · latest 53°F, as of Oct 17, 10:00 PM CDT
Measured at USDA NRCS SCAN station Cache Junction, 10 mi away. Daily averages: Thu 51°, Fri 51°.
4-inch depth
52°F 50–55°F
24-hour average · latest 54°F, as of Oct 17, 10:00 PM CDT
Measured at USDA NRCS SCAN station Cache Junction, 10 mi away. Daily averages: Thu 53°, Fri 52°.
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 84308 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 52°F at 4 inches. Fall pre-emergent window is mostly past. Next: spring, when soil reaches 50°F (typically mid-April to mid-May).
Fertilizer window
Lawn region: Mountain West and High Plains. Timing only; always follow the product label.
- Kentucky bluegrass (cool-season): Early fall: Around Labor Day (late August–September); Late fall: Late October–November, before the ground freezes; Late spring: Optional around Memorial Day. Avoid: Early-spring and midsummer feeding (pushes top growth, favors crabgrass).
Plant now
No vegetable planting windows are open this week.
Prune now
No frost-timed pruning windows are open this week.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | May 3 |
| 50% (the "average" last frost) | May 17 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 6 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Sep 1 |
| 50% (the "average" first frost) | Sep 18 |
| 90% (late: most years have frozen by now) | Oct 4 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Jun 5 | Sep 6 |
| 32°F (freeze) | May 17 | Sep 18 |
| 28°F (hard freeze) | May 2 | Oct 1 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 84308
Dates count from your average last spring frost (May 17) and first fall frost (Sep 18). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Mar 22–Apr 5 | May 24–Jun 7 (transplant) | – |
| Pepper (sweet and hot) | Mar 8–22 | May 31–Jun 14 (transplant) | – |
| Eggplant | Mar 8–22 | May 31–Jun 14 (transplant) | – |
| Tomatillo | Mar 22–Apr 5 | May 24–Jun 7 (transplant) | – |
| Lettuce | Mar 22–Apr 5 | Apr 26–May 17 (transplant) Apr 19–May 31 (sow outdoors) | Jul 24–Aug 14 (transplant) Jul 10–Aug 7 (sowing) |
| Spinach | – | Apr 5–26 (sow outdoors) | Jul 24–Aug 14 (sowing) |
| Kale | Mar 22–Apr 5 | Apr 19–May 3 (transplant) Apr 19–May 3 (sow outdoors) | Jun 26–Jul 24 (transplant) Jun 12–Jul 10 (sowing) |
| Collards | Mar 22–Apr 5 | Apr 19–May 17 (transplant) Apr 19–May 17 (sow outdoors) | Jun 26–Jul 24 (transplant) Jun 12–Jul 10 (sowing) |
| Broccoli | Mar 8–22 | Apr 19–May 3 (transplant) | Jun 12–Jul 10 (transplant) |
| Cabbage | Mar 8–22 | Apr 19–May 3 (transplant) | Jun 12–Jul 10 (transplant) |
| Cauliflower | Mar 8–22 | May 3–17 (transplant) | Jun 12–Jul 10 (transplant) |
| Brussels sprouts | Feb 22–Mar 8 | Apr 19–May 3 (transplant) | May 29–Jun 19 (transplant) |
| Kohlrabi | Mar 22–Apr 5 | Apr 19–May 3 (transplant) Apr 19–May 3 (sow outdoors) | Jul 10–24 (sowing) |
| Bok choy / Asian greens | – | Apr 19–May 3 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Arugula | – | Apr 19–May 17 (sow outdoors) | Jul 24–Aug 21 (sowing) |
| Mustard greens | – | Apr 19–May 10 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Swiss chard | Apr 5–19 | May 3–24 (transplant) May 3–31 (sow outdoors) | Jul 10–24 (sowing) |
| Beet | – | Apr 19–May 17 (sow outdoors) | Jul 10–24 (sowing) |
| Carrot | – | Apr 26–May 24 (sow outdoors) | Jun 26–Jul 10 (sowing) |
| Radish | – | Apr 12–May 24 (sow outdoors) | Aug 7–21 (sowing) |
| Turnip | – | Apr 19–May 10 (sow outdoors) | Jul 10–24 (sowing) |
| Parsnip | – | Apr 26–May 17 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 22–Apr 19 (sow outdoors) | Jun 26–Jul 10 (sowing) |
| Onion (bulbing) | Feb 22–Mar 8 | Apr 5–19 (transplant) | – |
| Green onion / scallion | – | Apr 5–May 3 (sow outdoors) | Jul 10–24 (sowing) |
| Leek | Feb 22–Mar 8 | Apr 19–May 3 (transplant) | – |
| Garlic | – | – | Aug 7–Sep 4 (sowing) |
| Shallot | – | Apr 5–19 (transplant) | Aug 7–Sep 4 (sowing) |
| Potato | – | Apr 19–May 3 (transplant) | May 29–Jun 12 (transplant) |
| Sweet potato | – | Jun 7–21 (transplant) | – |
| Sweet corn | – | May 24–Jun 7 (sow outdoors) | – |
| Bean, bush (snap) | – | May 24–Jun 7 (sow outdoors) | – |
| Bean, pole | – | May 24–Jun 7 (sow outdoors) | – |
| Lima bean | – | May 31–Jun 14 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 7–28 (sow outdoors) | – |
| Cucumber | Apr 19–26 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Summer squash / zucchini | Apr 19–26 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Winter squash | Apr 19–26 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Pumpkin | – | May 24–Jun 7 (sow outdoors) | – |
| Watermelon | Apr 19–26 | May 31–Jun 14 (transplant) May 31–Jun 14 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 19–26 | May 31–Jun 14 (transplant) May 31–Jun 14 (sow outdoors) | – |
| Okra | Apr 5–19 | May 31–Jun 14 (transplant) May 31–Jun 14 (sow outdoors) | – |
| Celery | Feb 22–Mar 8 | May 24–31 (transplant) | – |
| Basil | Apr 5–19 | May 24–Jun 7 (transplant) May 24–Jun 7 (sow outdoors) | – |
| Cilantro | – | May 3–31 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Parsley | Mar 8–22 | May 3–17 (transplant) Apr 26–May 17 (sow outdoors) | – |
| Dill | – | May 17–31 (sow outdoors) | Jul 24–Aug 7 (sowing) |
| Sunflower | – | May 17–31 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 19–May 3 (transplant) | – |
| Rhubarb (crowns) | – | Apr 19–May 3 (transplant) | – |
| Strawberry (plants) | – | Apr 19–May 3 (transplant) | Jul 10–Aug 7 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Where these numbers come from
Station: Trenton, UT (NOAA GHCN-Daily ID USC00428828), elevation 4,455 ft, 4.5 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Richmond, UT | 9 mi | May 11 | Oct 5 |
| Preston, ID | 10 mi | May 16 | Sep 28 |
| Cutler Dam, UT | 10 mi | May 3 | Oct 12 |
The average last-frost dates of these stations span 14 days, a rough guide to local variation. See data sources & methods.
Frost questions for 84308
When is the last frost in 84308?
The average (50% chance) last spring freeze of 32°F for ZIP 84308 is May 17. For a more cautious planting date, use June 6, when only 1 year in 10 still sees a later freeze.
When is the first frost in 84308?
The average first fall freeze is September 18. In 1 year in 10 it comes by September 1.
What hardiness zone is 84308?
ZIP 84308 is in USDA zone 6a (-10 to -5°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 84308 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
84338 Trenton 84305 Clarkston 84320 Lewiston 84327 Cache 83286 Weston 84333 Richmond 84304 Cache 83237 Franklin
Other ZIP codes in Cache County
84304 84305 84318 84319 84320 84321 84322 84325 84326 84327 84328 84332 84333 84335 84338 84339 84341 All Cache County frost dates · Utah frost dates
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