Frost dates for 84624Delta, UT
The average last spring frost in Delta is May 16 and the average first fall frost is September 29, giving a typical growing season of about 137 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 16
- Average first fall frost
- Sep 29
- Growing season
- 137 days
Safer after Jun 5 (1-in-10 risk)
Possible by Sep 16 (1-in-10 risk)
Last frost typically in 201 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 12 · May 29 · Jun 16 | Sep 8 · Sep 22 · Oct 2 | 114 days | 100% |
| Frost / freeze (32°F) | Apr 29 · May 16 · Jun 5 | Sep 16 · Sep 29 · Oct 11 | 137 days | 100% |
| Hard freeze (28°F) | Apr 17 · May 2 · May 19 | Sep 27 · Oct 9 · Oct 23 | 160 days | 100% |
Planting calendar for Delta
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 15 – Jun 21 |
| Tomatoes | Transplant outdoors | Jun 1 – Jun 9 |
| Peppers | Start seeds indoors | Apr 15 – May 16 |
| Peppers | Transplant outdoors | Jun 15 – Jul 16 |
| Eggplant | Start seeds indoors | May 2 – May 31 |
| Eggplant | Transplant outdoors | Jun 15 – Jul 16 |
| Cucumbers | Sow outdoors | Jun 15 – Jun 19 |
| Summer squash | Sow outdoors | Jun 1 – Jul 16 |
| Winter squash & pumpkins | Sow outdoors | Jun 15 – Jul 16 |
| Snap beans | Sow outdoors | Jun 1 – Jul 12 |
| Sweet corn | Sow outdoors | Jun 1 – Jun 9 |
| Watermelon & cantaloupe | Sow outdoors | Jun 15 – Jul 16 |
| Okra | Sow outdoors | Jun 8 – Jul 1 |
| Peas | Sow outdoors (spring) | Apr 15 – May 31 |
| Potatoes | Plant outdoors (spring) | Apr 15 – Jun 15 |
| Onions | Start seeds indoors (spring) | Mar 4 – Mar 31 |
| Onions | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (spring) | Mar 28 – May 1 |
| Broccoli | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (fall) | May 30 – Jun 9 |
| Broccoli | Transplant outdoors (fall) | Jun 29 – Jul 10 |
| Cabbage | Start seeds indoors (spring) | Mar 18 – Apr 15 |
| Cabbage | Transplant outdoors (spring) | Apr 15 – May 16 |
| Cabbage | Start seeds indoors (fall) | May 20 – Jun 19 |
| Cabbage | Transplant outdoors (fall) | Jun 19 – Jul 20 |
| Leaf lettuce | Sow outdoors (spring) | Apr 15 – Jul 1 |
| Leaf lettuce | Sow outdoors (fall) | Jun 19 – Aug 5 |
| Spinach | Sow outdoors (spring) | Apr 8 – May 22 |
| Spinach | Sow outdoors (fall) | Jul 6 – Aug 10 |
| Radishes | Sow outdoors (spring) | Apr 15 – Jun 5 |
| Radishes | Sow outdoors (fall) | Jun 19 – Aug 20 |
| Kale | Sow outdoors (spring) | May 2 – May 22 |
| Kale | Sow outdoors (fall) | Jun 12 – Jul 20 |
| Carrots | Sow outdoors (spring) | May 16 – Jul 1 |
| Carrots | Sow outdoors (fall) | May 20 – Jul 5 |
| Garlic | Plant outdoors (fall) | Sep 19 – Oct 20 |
Where these dates come from
ZIP code 84624 is matched to the NOAA station Delta, UT, 6.3 km away, at 4,620 ft elevation (104 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Delta, UT (used) | 4,620 ft | May 16 | Sep 29 |
| Deseret, UT | 4,590 ft | May 14 | Sep 30 |
| Oak City, UT | 5,095 ft | May 2 | Oct 13 |
| Scipio, UT | 5,314 ft | May 22 | Sep 25 |
Frost dates near Delta
- Hinckley, UT 84635 · last May 14, first Sep 30
- Oak City, UT 84649 · last May 2, first Oct 13
- Lynndyl, UT 84640 · last May 2, first Oct 13
- Leamington, UT 84638 · last May 2, first Oct 13
- Holden, UT 84636 · last May 4, first Oct 14
- Scipio, UT 84656 · last May 22, first Sep 25
- Fillmore, UT 84631 · last May 4, first Oct 14
- Levan, UT 84639 · last May 10, first Oct 7
Frequently asked questions
- When is the last frost in Delta, UT?
- For ZIP code 84624, the average last spring frost (32°F) is May 16, based on NOAA 1991-2020 climate normals for the Delta, UT weather station. There is a 1-in-10 chance of a frost after June 5.
- When is the first frost in Delta, UT?
- The average first fall frost (32°F) is September 29. There is a 1-in-10 chance of frost by September 16, so tender plants are at risk from that point on.
- How long is the growing season in 84624?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 137 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.