Frost dates for 84158Salt Lake City, UT
The average last spring frost in Salt Lake City is May 7 and the average first fall frost is October 14, giving a typical growing season of about 158 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 7
- Average first fall frost
- Oct 14
- Growing season
- 158 days
Safer after May 27 (1-in-10 risk)
Possible by Sep 29 (1-in-10 risk)
Last frost typically in 193 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 8 · May 25 · Jun 11 | Sep 15 · Oct 1 · Oct 15 | 128 days | 100% |
| Frost / freeze (32°F) | Apr 21 · May 7 · May 27 | Sep 29 · Oct 14 · Oct 27 | 158 days | 100% |
| Hard freeze (28°F) | Apr 4 · Apr 21 · May 6 | Oct 11 · Oct 26 · Nov 9 | 188 days | 100% |
Planting calendar for Salt Lake City
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 24 |
| 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 – Jul 4 |
| Summer squash | Sow outdoors | May 23 – Jul 7 |
| Winter squash & pumpkins | Sow outdoors | Jun 6 – Jul 7 |
| Snap beans | Sow outdoors | May 23 – Jul 27 |
| Sweet corn | Sow outdoors | May 23 – Jun 24 |
| 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 14 – Jun 24 |
| Broccoli | Transplant outdoors (fall) | Jul 14 – Jul 25 |
| Cabbage | Start seeds indoors (spring) | Mar 9 – Apr 6 |
| Cabbage | Transplant outdoors (spring) | Apr 6 – May 7 |
| Cabbage | Start seeds indoors (fall) | Jun 4 – Jul 4 |
| Cabbage | Transplant outdoors (fall) | Jul 4 – Aug 4 |
| Leaf lettuce | Sow outdoors (spring) | Apr 6 – Jun 22 |
| Leaf lettuce | Sow outdoors (fall) | Jul 4 – Aug 20 |
| Spinach | Sow outdoors (spring) | Mar 30 – May 13 |
| Spinach | Sow outdoors (fall) | Jul 21 – Aug 25 |
| Radishes | Sow outdoors (spring) | Apr 6 – May 27 |
| Radishes | Sow outdoors (fall) | Jul 4 – Sep 4 |
| Kale | Sow outdoors (spring) | Apr 23 – May 13 |
| Kale | Sow outdoors (fall) | Jun 27 – Aug 4 |
| Carrots | Sow outdoors (spring) | May 7 – Jun 22 |
| Carrots | Sow outdoors (fall) | Jun 4 – Jul 20 |
| Garlic | Plant outdoors (fall) | Oct 4 – Nov 4 |
Where these dates come from
ZIP code 84158 is matched to the NOAA station Mtn Dell Dam, UT, 4 km away, at 5,420 ft elevation (75 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Mtn Dell Dam, UT (used) | 5,420 ft | May 7 | Oct 14 |
| Salt Lake City E Bench, UT | 4,850 ft | Apr 25 | Oct 18 |
| City Creek Wtp, UT | 5,340 ft | May 13 | Oct 7 |
| Salt Lake Triad Ctr, UT | 4,280 ft | Mar 31 | Nov 8 |
Frost dates near Salt Lake City
- Salt Lake City, UT 84113 · last Apr 25, first Oct 24
- Bountiful, UT 84010 · last Apr 24, first Oct 19
- North Salt Lake, UT 84054 · last Apr 8, first Oct 31
- Sandy, UT 84090 · last Apr 8, first Oct 31
- Woods Cross, UT 84087 · last Apr 24, first Oct 19
- Park City, UT 84098 · last May 29, first Sep 25
- Midvale, UT 84047 · last Apr 18, first Oct 22
- Centerville, UT 84014 · last Apr 24, first Oct 19
Frequently asked questions
- When is the last frost in Salt Lake City, UT?
- For ZIP code 84158, the average last spring frost (32°F) is May 7, based on NOAA 1991-2020 climate normals for the Mtn Dell Dam, UT weather station. There is a 1-in-10 chance of a frost after May 27.
- When is the first frost in Salt Lake City, UT?
- The average first fall frost (32°F) is October 14. There is a 1-in-10 chance of frost by September 29, so tender plants are at risk from that point on.
- How long is the growing season in 84158?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 158 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.