Frost Dates for Salt Lake City, UT 84121
Last spring frost June 13 · First fall frost September 15 · 94 frost-free days · USDA Zone 6a
ZIP 84121 has about 38,900 people, one of 24 ZIP codes in Salt Lake City.
Short season: 94 frost-free days. Spring frost risk spans May 28–June 28 (31 days). Fall frost risk spans August 26–October 4 (39 days).
Frost probability for 84121
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | June 28 | June 13 | May 28 |
| Fall (first frost) | August 26 | September 15 | October 4 |
Dates come from NOAA 1971–2000 freeze probabilities at ALTA (6.5 km away); the 50% date is the median year.
Which crops fit a 94-day season in Salt Lake City
In Salt Lake City (94 frost-free days, a short season), 28 of 56 planner crops fit outright, 14 get two plantings, 5 need an indoor start, 8 don't reliably mature, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | May 9 | Jun 27–Jul 4 | 52 | no-fit: Needs 80 days; Salt Lake City has 52 after Jun 27. | — |
| Pepper | May 2 | Jun 27–Jul 4 | 52 | no-fit: Needs 75 days; Salt Lake City has 52 after Jun 27. | — |
| Lettuce | Apr 18 | May 16–May 23 | 129 | two-plantings: Plant May 16 and again by Jul 25; both mature before Sep 22. | Jul 25 |
| Carrots | — | May 23–May 30 | 136 | fits: 70 days to maturity, 136 available after May 23. | Jul 14 |
| Cucumber | May 23 | Jun 27–Jul 4 | 66 | fits: 60 days to maturity, 66 available after Jun 27. | — |
| Beans | — | Jun 20–Jul 4 | 80 | fits: 60 days to maturity, 80 available after Jun 20. | Jun 26 |
| Peas | — | Apr 18–Jun 27 | 157 | fits: 65 days to maturity, 157 available after Apr 18. | Jul 5 |
| Zucchini | May 30 | Jun 27–Jul 4 | 66 | fits: 55 days to maturity, 66 available after Jun 27. | — |
| Onion | Mar 21 | May 16–May 30 | 129 | fits: 100 days to maturity, 129 available after May 16. | — |
| Spinach | — | Apr 18–Jun 6 | 171 | two-plantings: Plant Apr 18 and again by Aug 13; both mature before Oct 6. | Aug 13 |
| Kale | Apr 4 | May 16–May 30 | 143 | two-plantings: Plant May 16 and again by Jul 29; both mature before Oct 6. | Jul 29 |
| Broccoli | Apr 18 | May 16–May 30 | 129 | fits: 80 days to maturity, 129 available after May 16. | Jun 20 |
| Cabbage | Apr 18 | May 16–May 30 | 143 | fits: 70 days to maturity, 143 available after May 16. | Jul 14 |
| Radish | — | Apr 18–Jul 11 | 157 | two-plantings: Plant Apr 18 and again by Aug 14; both mature before Sep 22. | Aug 14 |
| Beets | — | Apr 18–Jul 11 | 157 | two-plantings: Plant Apr 18 and again by Jul 15; both mature before Sep 22. | Jul 15 |
| Potatoes | — | May 30–Jun 6 | 115 | fits: 90 days to maturity, 115 available after May 30. | — |
| Garlic | — | Sep 15 | 199 | overwinter: Plant Sep 15 to Oct 6; harvest the following summer. | Oct 6 |
| Strawberry | — | May 9–Jul 4 | 150 | perennial: A perennial: plant May 9; it fruits from the following year and keeps producing for several years. | — |
| Corn | May 16 | Jun 20–Jun 27 | 66 | head-start: Even planted out Jun 20, the outdoor season is about 9 days short; choose an early variety or grow under cover. | — |
| Pumpkin | May 30 | Jun 27–Jun 27 | 59 | no-fit: Needs 100 days; Salt Lake City has 59 after Jun 27. | — |
| Cauliflower | May 2 | Jun 6–Jun 20 | 108 | fits: 75 days to maturity, 108 available after Jun 6. | Jun 25 |
| Swiss Chard | Apr 18 | May 30–May 30 | 115 | fits: 55 days to maturity, 115 available after May 30. | Jul 15 |
| Arugula | — | Apr 18–Jul 11 | 171 | two-plantings: Plant Apr 18 and again by Aug 13; both mature before Oct 6. | Aug 13 |
| Brussel Sprouts | Apr 18 | May 16–May 30 | 143 | fits: 100 days to maturity, 143 available after May 16. | Jun 14 |
| Butternut Squash | May 30 | Jun 27–Jul 4 | 59 | no-fit: Needs 100 days; Salt Lake City has 59 after Jun 27. | — |
| Eggplant | Apr 25 | Jun 27–Jul 4 | 52 | head-start: Even planted out Jun 27, the outdoor season is about 18 days short; choose an early variety or grow under cover. | — |
| Okra | May 16 | Jun 20–Jun 27 | 73 | fits: 55 days to maturity, 73 available after Jun 20. | Jun 24 |
| Basil | May 9 | Jul 4–Jul 4 | 59 | head-start: Even planted out Jul 4, the outdoor season is about 1 days short; choose an early variety or grow under cover. | — |
| Cilantro | — | May 16–Jun 6 | 129 | two-plantings: Plant May 16 and again by Jul 20; both mature before Sep 22. | Jul 20 |
| Parsley | Apr 4 | Jun 20–Jun 27 | 94 | fits: 70 days to maturity, 94 available after Jun 20. | Jun 30 |
| Celery | Apr 4 | Jun 20–Jul 4 | 94 | no-fit: Needs 120 days; Salt Lake City has 94 after Jun 20. | — |
| Scallions | Apr 4 | May 16–May 30 | 143 | two-plantings: Plant May 16 and again by Jul 24; both mature before Oct 6. | Jul 24 |
| Turnip | — | May 16–May 30 | 143 | two-plantings: Plant May 16 and again by Aug 3; both mature before Oct 6. | Aug 3 |
| Kohlrabi | — | May 2–May 16 | 157 | two-plantings: Plant May 2 and again by Jul 29; both mature before Oct 6. | Jul 29 |
| Bok Choy | May 16 | Jun 6–Jun 13 | 108 | two-plantings: Plant Jun 6 and again by Jul 25; both mature before Sep 22. | Jul 25 |
| Collards | Apr 4 | May 16–May 30 | 143 | two-plantings: Plant May 16 and again by Jul 24; both mature before Oct 6. | Jul 24 |
| Cantaloupe | May 30 | Jun 27–Jul 4 | 52 | no-fit: Needs 85 days; Salt Lake City has 52 after Jun 27. | — |
| Chives | Mar 21 | Jun 20–Jun 27 | 108 | fits: 90 days to maturity, 108 available after Jun 20. | — |
| Dill | — | Apr 18–Jul 11 | 157 | two-plantings: Plant Apr 18 and again by Jul 15; both mature before Sep 22. | Jul 15 |
| Oregano | Apr 4 | Jun 20–Jun 27 | 108 | fits: 80 days to maturity, 108 available after Jun 20. | — |
| Rosemary | Mar 21 | Jun 20–Jun 27 | 94 | fits: 80 days to maturity, 94 available after Jun 20. | — |
| Sage | Apr 18 | Jun 20–Jun 27 | 108 | fits: 75 days to maturity, 108 available after Jun 20. | — |
| Thyme | Apr 4 | Jun 20–Jun 27 | 108 | fits: 90 days to maturity, 108 available after Jun 20. | — |
| Calendula | May 2 | May 30–Jun 13 | 115 | two-plantings: Plant May 30 and again by Jul 20; both mature before Sep 22. | Jul 20 |
| Cosmos | May 16 | Jun 13–Jun 27 | 80 | fits: 60 days to maturity, 80 available after Jun 13. | Jun 19 |
| Lavender | Mar 21 | Jun 13–Jun 27 | 115 | fits: 90 days to maturity, 115 available after Jun 13. | — |
| Marigolds | May 2 | Jun 13–Jun 20 | 80 | fits: 50 days to maturity, 80 available after Jun 13. | Jun 29 |
| Melons | May 30 | Jun 27–Jul 4 | 52 | no-fit: Needs 85 days; Salt Lake City has 52 after Jun 27. | — |
| Mint | — | Jun 13–Jun 27 | 115 | fits: 90 days to maturity, 115 available after Jun 13. | — |
| Nasturtiums | May 16 | Jun 13–Jun 20 | 80 | fits: 55 days to maturity, 80 available after Jun 13. | Jun 24 |
| Pole Beans | — | Jun 20–Jul 4 | 73 | fits: 65 days to maturity, 73 available after Jun 20. | — |
| Spaghetti Squash | May 30 | Jun 27–Jul 4 | 59 | no-fit: Needs 90 days; Salt Lake City has 59 after Jun 27. | — |
| Sunflowers | — | Jun 13–Jun 27 | 80 | fits: 70 days to maturity, 80 available after Jun 13. | — |
| Tomatillos | Apr 18 | Jun 20–Jun 27 | 59 | head-start: Even planted out Jun 20, the outdoor season is about 16 days short; choose an early variety or grow under cover. | — |
| Watermelon | May 30 | Jun 20–Jun 27 | 59 | head-start: Even planted out Jun 20, the outdoor season is about 21 days short; choose an early variety or grow under cover. | — |
| Yellow Squash | May 30 | Jun 27–Jul 4 | 66 | fits: 55 days to maturity, 66 available after Jun 27. | — |
| Zinnias | May 16 | Jun 13–Jun 27 | 80 | fits: 60 days to maturity, 80 available after Jun 13. | Jun 19 |
Month by month in Salt Lake City
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start the slowest-growing crops indoors: onions, leeks, and celery (10–12 weeks before last frost). |
| March | Start indoors: Chives (Mar 21), Lavender (Mar 21), Onion (Mar 21), Rosemary (Mar 21). |
| April | Start indoors: Celery (Apr 4), Collards (Apr 4), Kale (Apr 4), Oregano (Apr 4), Parsley (Apr 4), Scallions (Apr 4), +9 more. Direct sow from: Arugula (Apr 18), Beets (Apr 18), Dill (Apr 18), Peas (Apr 18), Radish (Apr 18), Spinach (Apr 18). |
| May | Start indoors: Calendula (May 2), Cauliflower (May 2), Marigolds (May 2), Pepper (May 2), Basil (May 9), Tomato (May 9), +15 more. Direct sow from: Kohlrabi (May 2), Cilantro (May 16), Turnip (May 16), Carrots (May 23), Potatoes (May 30). Transplant from: Broccoli (May 16), Brussel Sprouts (May 16), Cabbage (May 16), Collards (May 16), Kale (May 16), Lettuce (May 16), +4 more. Plant: Strawberry (May 9). |
| June | Direct sow from: Sunflowers (Jun 13), Beans (Jun 20), Pole Beans (Jun 20). Transplant from: Bok Choy (Jun 6), Cauliflower (Jun 6), Cosmos (Jun 13), Lavender (Jun 13), Marigolds (Jun 13), Mint (Jun 13), +24 more. Last frost around June 13. Last sowing dates: Brussel Sprouts (Jun 14), Cosmos (Jun 19), Zinnias (Jun 19), Broccoli (Jun 20), Nasturtiums (Jun 24), Okra (Jun 24), +4 more. |
| July | Transplant from: Basil (Jul 4). Last sowing dates: Peas (Jul 5), Cabbage (Jul 14), Carrots (Jul 14), Beets (Jul 15), Dill (Jul 15), Swiss Chard (Jul 15), +8 more. |
| August | Last sowing dates: Turnip (Aug 3), Arugula (Aug 13), Spinach (Aug 13), Radish (Aug 14). |
| September | Direct sow from: Garlic (Sep 15). First frost around September 15. |
| October | Last sowing dates: Garlic (Oct 6). |
| November | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
| December | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
Frequently Asked Questions
What is the last frost date for Salt Lake City, UT (ZIP 84121)?
The median last spring frost date for Salt Lake City, UT (ZIP code 84121) is around June 13. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area. One year in ten frost ends before May 28; one in ten it runs past June 28.
What is the first fall frost date in Salt Lake City, UT?
The median first fall frost date for Salt Lake City, UT is around September 15. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses. The first frost arrives around August 26 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Salt Lake City, UT?
The frost-free growing season in Salt Lake City is about 94 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side. In Salt Lake City (94 frost-free days, a short season), 28 of 56 planner crops fit outright, 14 get two plantings, 5 need an indoor start, 8 don't reliably mature, 1 crop is perennial.
What USDA hardiness zone is Salt Lake City, UT?
Salt Lake City, UT is in USDA hardiness zone 6a (2023 USDA Plant Hardiness Zone Map). Zones come from the average coldest winter temperature, so they tell you which perennials survive the winter; the frost dates on this page tell you when to plant.
When should I start tomatoes indoors in Salt Lake City, UT?
Start tomatoes indoors May 9 and plant out Jun 27 in Salt Lake City. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Salt Lake City?
Two: plant May 16 and again by Jul 25; both mature before Sep 22.
When do I plant garlic in Salt Lake City?
Sep 15 to Oct 6; it overwinters and is ready the following summer.
Can I grow Celery in Salt Lake City?
Not reliably outdoors. Needs 120 days; Salt Lake City has 94 after Jun 20.
Which nearby ZIP has a longer season?
Salt Lake City (ZIP 84109) has 131 frost-free days, 37 more than Salt Lake City (ZIP 84121). See Salt Lake City ZIP 84109 frost dates
Nearby and related
- Frost dates for Salt Lake City, UT 84109 (5.3 mi)
- Frost dates for Alpine, UT 84004 (10 mi)
- Frost dates for Midvale, UT 84047 (10.1 mi)
- Frost dates for Sandy, UT 84070 (10.5 mi)
- Frost dates for American Fork, UT 84003 (11 mi)
- When to plant in Salt Lake City, UT: month-by-month guide
- When to plant in UT
- When to plant Beans in UT
- When to plant Strawberries in UT
- When to plant Beets in UT
- When to plant Broccoli in UT
- When to plant Carrots in UT
- When to plant Kale in UT
- Look up another ZIP