Frost dates for 84079Vernal, UT
The average last spring frost in Vernal is May 7 and the average first fall frost is October 6, giving a typical growing season of about 150 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 7
- Average first fall frost
- Oct 6
- Growing season
- 150 days
Safer after May 28 (1-in-10 risk)
Possible by Sep 23 (1-in-10 risk)
Last frost typically in 192 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | May 5 · May 23 · Jun 9 | Sep 13 · Sep 27 · Oct 8 | 126 days | 100% |
| Frost / freeze (32°F) | Apr 24 · May 7 · May 28 | Sep 23 · Oct 6 · Oct 20 | 150 days | 100% |
| Hard freeze (28°F) | Apr 11 · Apr 25 · May 11 | Oct 3 · Oct 18 · Oct 30 | 174 days | 100% |
Planting calendar for Vernal
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Apr 6 – Jun 12 |
| Tomatoes | Transplant outdoors | May 23 – Jun 16 |
| Peppers | Start seeds indoors | Apr 6 – May 7 |
| Peppers | Transplant outdoors | Jun 6 – Jul 7 |
| Eggplant | Start seeds indoors | Apr 23 – May 22 |
| Eggplant | Transplant outdoors | Jun 6 – Jul 7 |
| Cucumbers | Sow outdoors | Jun 6 – Jun 26 |
| Summer squash | Sow outdoors | May 23 – Jul 7 |
| Winter squash & pumpkins | Sow outdoors | Jun 6 – Jul 7 |
| Snap beans | Sow outdoors | May 23 – Jul 19 |
| Sweet corn | Sow outdoors | May 23 – Jun 16 |
| Watermelon & cantaloupe | Sow outdoors | Jun 6 – Jul 7 |
| Okra | Sow outdoors | May 30 – Jun 22 |
| Peas | Sow outdoors (spring) | Apr 6 – May 22 |
| Potatoes | Plant outdoors (spring) | Apr 6 – Jun 6 |
| Onions | Start seeds indoors (spring) | Feb 23 – Mar 22 |
| Onions | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (spring) | Mar 19 – Apr 22 |
| Broccoli | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (fall) | Jun 6 – Jun 16 |
| Broccoli | Transplant outdoors (fall) | Jul 6 – Jul 17 |
| Cabbage | Start seeds indoors (spring) | Mar 9 – Apr 6 |
| Cabbage | Transplant outdoors (spring) | Apr 6 – May 7 |
| Cabbage | Start seeds indoors (fall) | May 27 – Jun 26 |
| Cabbage | Transplant outdoors (fall) | Jun 26 – Jul 27 |
| Leaf lettuce | Sow outdoors (spring) | Apr 6 – Jun 22 |
| Leaf lettuce | Sow outdoors (fall) | Jun 26 – Aug 12 |
| Spinach | Sow outdoors (spring) | Mar 30 – May 13 |
| Spinach | Sow outdoors (fall) | Jul 13 – Aug 17 |
| Radishes | Sow outdoors (spring) | Apr 6 – May 27 |
| Radishes | Sow outdoors (fall) | Jun 26 – Aug 27 |
| Kale | Sow outdoors (spring) | Apr 23 – May 13 |
| Kale | Sow outdoors (fall) | Jun 19 – Jul 27 |
| Carrots | Sow outdoors (spring) | May 7 – Jun 22 |
| Carrots | Sow outdoors (fall) | May 27 – Jul 12 |
| Garlic | Plant outdoors (fall) | Sep 26 – Oct 27 |
Where these dates come from
ZIP code 84079 is matched to the NOAA station Vernal, UT, 1.8 km away, at 5,345 ft elevation (14 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Vernal, UT (used) | 5,345 ft | May 7 | Oct 6 |
| Vernal Municipal Ap, UT | 5,260 ft | May 6 | Oct 7 |
| Maeser 9Nw, UT | 6,448 ft | May 15 | Oct 5 |
| Jensen, UT | 4,736 ft | May 20 | Sep 25 |
Frost dates near Vernal
- Vernal, UT 84078 · last May 7, first Oct 6
- Jensen, UT 84035 · last May 20, first Sep 25
- Lapoint, UT 84039 · last May 7, first Oct 6
- Tridell, UT 84076 · last May 19, first Sep 29
- Randlett, UT 84063 · last May 2, first Oct 3
- Fort Duchesne, UT 84026 · last May 19, first Oct 2
- Whiterocks, UT 84085 · last May 19, first Sep 29
- Neola, UT 84053 · last May 19, first Sep 29
Frequently asked questions
- When is the last frost in Vernal, UT?
- For ZIP code 84079, the average last spring frost (32°F) is May 7, based on NOAA 1991-2020 climate normals for the Vernal, UT weather station. There is a 1-in-10 chance of a frost after May 28.
- When is the first frost in Vernal, UT?
- The average first fall frost (32°F) is October 6. There is a 1-in-10 chance of frost by September 23, so tender plants are at risk from that point on.
- How long is the growing season in 84079?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 150 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.