Frost dates for 84744Koosharem, UT
The average last spring frost in Koosharem is June 6 and the average first fall frost is September 21, giving a typical growing season of about 104 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 6
- Average first fall frost
- Sep 21
- Growing season
- 104 days
Safer after Jun 26 (1-in-10 risk)
Possible by Sep 5 (1-in-10 risk)
Last frost typically in 222 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) | Jun 5 · Jun 22 · Jul 11 | Aug 26 · Sep 10 · Sep 23 | 79 days | 100% |
| Frost / freeze (32°F) | May 24 · Jun 6 · Jun 26 | Sep 5 · Sep 21 · Oct 2 | 104 days | 100% |
| Hard freeze (28°F) | May 7 · May 26 · Jun 10 | Sep 14 · Sep 29 · Oct 12 | 126 days | 100% |
Planting calendar for Koosharem
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 | May 6 – Jul 12 |
| Tomatoes | Transplant outdoors | Jun 22 – Jun 1 |
| Peppers | Start seeds indoors | May 6 – Jun 6 |
| Peppers | Transplant outdoors | Jul 6 – Aug 6 |
| Eggplant | Start seeds indoors | May 23 – Jun 21 |
| Eggplant | Transplant outdoors | Jul 6 – Aug 6 |
| Cucumbers | Sow outdoors | Jul 6 – Jun 11 |
| Summer squash | Sow outdoors | Jun 22 – Aug 6 |
| Winter squash & pumpkins | Sow outdoors | Jul 6 – Aug 6 |
| Snap beans | Sow outdoors | Jun 22 – Jul 4 |
| Sweet corn | Sow outdoors | Jun 22 – Jun 1 |
| Watermelon & cantaloupe | Sow outdoors | Jul 6 – Aug 6 |
| Okra | Sow outdoors | Jun 29 – Jul 22 |
| Peas | Sow outdoors (spring) | May 6 – Jun 21 |
| Potatoes | Plant outdoors (spring) | May 6 – Jul 6 |
| Onions | Start seeds indoors (spring) | Mar 25 – Apr 21 |
| Onions | Transplant outdoors (spring) | May 23 – Jun 21 |
| Broccoli | Start seeds indoors (spring) | Apr 18 – May 22 |
| Broccoli | Transplant outdoors (spring) | May 23 – Jun 21 |
| Broccoli | Start seeds indoors (fall) | May 22 – Jun 1 |
| Broccoli | Transplant outdoors (fall) | Jun 21 – Jul 2 |
| Cabbage | Start seeds indoors (spring) | Apr 8 – May 6 |
| Cabbage | Transplant outdoors (spring) | May 6 – Jun 6 |
| Cabbage | Start seeds indoors (fall) | May 12 – Jun 11 |
| Cabbage | Transplant outdoors (fall) | Jun 11 – Jul 12 |
| Leaf lettuce | Sow outdoors (spring) | May 6 – Jul 22 |
| Leaf lettuce | Sow outdoors (fall) | Jun 11 – Jul 28 |
| Spinach | Sow outdoors (spring) | Apr 29 – Jun 12 |
| Spinach | Sow outdoors (fall) | Jun 28 – Aug 2 |
| Radishes | Sow outdoors (spring) | May 6 – Jun 26 |
| Radishes | Sow outdoors (fall) | Jun 11 – Aug 12 |
| Kale | Sow outdoors (spring) | May 23 – Jun 12 |
| Kale | Sow outdoors (fall) | Jun 4 – Jul 12 |
| Carrots | Sow outdoors (spring) | Jun 6 – Jul 22 |
| Carrots | Sow outdoors (fall) | May 12 – Jun 27 |
| Garlic | Plant outdoors (fall) | Sep 11 – Oct 12 |
Where these dates come from
ZIP code 84744 is matched to the NOAA station Koosharem, UT, 0.3 km away, at 6,930 ft elevation (11 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Koosharem, UT (used) | 6,930 ft | Jun 6 | Sep 21 |
| Loa, UT | 7,070 ft | May 31 | Sep 21 |
| Angle, UT | 6,410 ft | Jun 17 | Sep 12 |
| Marysvale, UT | 5,845 ft | May 24 | Sep 25 |
Frost dates near Koosharem
- Greenwich, UT 84732 · last Jun 6, first Sep 21
- Loa, UT 84747 · last May 31, first Sep 21
- Monroe, UT 84754 · last May 21, first Sep 24
- Annabella, UT 84711 · last May 21, first Sep 24
- Lyman, UT 84749 · last May 31, first Sep 21
- Elsinore, UT 84724 · last May 21, first Sep 24
- Glenwood, UT 84730 · last May 21, first Sep 24
- Richfield, UT 84701 · last May 21, first Sep 24
Frequently asked questions
- When is the last frost in Koosharem, UT?
- For ZIP code 84744, the average last spring frost (32°F) is June 6, based on NOAA 1991-2020 climate normals for the Koosharem, UT weather station. There is a 1-in-10 chance of a frost after June 26.
- When is the first frost in Koosharem, UT?
- The average first fall frost (32°F) is September 21. There is a 1-in-10 chance of frost by September 5, so tender plants are at risk from that point on.
- How long is the growing season in 84744?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 104 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.