West Valley City, Utah: planting zone & frost dates
West Valley City is in USDA plant hardiness zone 7b, where the average coldest winter night reaches 5 to 10°F (-15.0 to -12.2°C). The typical last spring frost is around Apr 16 and the first fall frost around Oct 25.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Apr 30 | Oct 17 |
| Typical planning date (30% risk) | Apr 16 | Oct 25 |
| Median (50%) | Apr 8 | Oct 31 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station SALT LAKE CITY INTL AP, UT (USW00024127), 6.6 mi (10.6 km) from the city center and 121 ft lower than the city center (-37 m). Record used for the 1991–2020 normals: 29 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across West Valley City
All 6 ZIP codes covering West Valley City are in zone 7b.
Vegetable planting calendar for West Valley City
Dates are counted from the 30%-risk frost dates above (last frost Apr 16, first frost Oct 25). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Feb 19 – Mar 5 | Apr 23 – May 7 | — | — |
| Pepper | Feb 5 – Feb 19 | Apr 30 – May 14 | — | — |
| Lettuce | Mar 5 – Mar 19 | Apr 2 – Apr 23 | Mar 19 – Apr 30 | Aug 16 – Sep 13 |
| Green Beans | — | — | Apr 23 – May 28 | Aug 2 – Aug 16 |
| Sweet Corn | — | — | Apr 23 – May 21 | — |
| Zucchini & Summer Squash | Mar 19 – Mar 26 | Apr 23 – May 7 | Apr 23 – May 14 | Aug 2 – Aug 16 |
| Cucumber | Mar 19 – Mar 26 | Apr 30 – May 7 | Apr 23 – May 14 | Aug 2 – Aug 16 |
| Carrot | — | — | Mar 26 – Apr 30 | Aug 2 – Aug 16 |
| Onion | Jan 22 – Feb 5 | Mar 19 – Apr 2 | — | — |
| Potato | — | Mar 19 – Apr 9 | — | — |
| Basil | Mar 5 – Mar 19 | Apr 30 – May 14 | Apr 30 – May 21 | — |
| Spinach | — | — | Mar 5 – Apr 2 | Aug 30 – Sep 27 |
| Kale | Feb 19 – Mar 5 | Mar 19 – Apr 9 | Mar 19 – Apr 9 | Aug 16 – Sep 13 |
| Broccoli | Feb 19 – Mar 5 | Apr 2 – Apr 23 | — | Aug 2 – Aug 16 |
| Peas | — | — | Mar 5 – Mar 26 | Aug 16 – Aug 30 |
| Eggplant | Feb 5 – Feb 19 | Apr 30 – May 14 | — | — |
| Cabbage | Feb 19 – Mar 5 | Mar 19 – Apr 2 | — | Aug 2 – Aug 16 |
| Radish | — | — | Mar 12 – Apr 30 | Sep 13 – Oct 11 |
| Strawberry | — | Mar 19 – Apr 9 | — | — |
| Beets | — | — | Mar 26 – May 7 | Aug 16 – Aug 30 |
Nearby cities in Utah
- West Jordan — zone 7b, last frost Apr 25, first frost Oct 16
- Salt Lake City — zone 7b, last frost Apr 16, first frost Oct 25
- South Jordan — zone 7a, last frost Apr 25, first frost Oct 16
- Sandy — zone 7b, last frost May 8, first frost Oct 16
- Lehi — zone 7a, last frost May 8, first frost Oct 2
- Layton — zone 7a, last frost Apr 27, first frost Oct 13
More: all Utah cities · other zone 7b cities: New York, NY, Philadelphia, PA, Oklahoma City, OK, Nashville, TN, Washington, DC, Baltimore, MD, Albuquerque, NM, Tulsa, OK
West Valley City gardening questions
When is the last frost in West Valley City, UT?
Plan around Apr 16. At NOAA's Salt Lake City Int'l Airport, UT station, 6.6 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Apr 8, and after Apr 30 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Mar 15. The 90% and 10% dates are 44 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in West Valley City, UT?
Start seeds indoors Feb 19 – Mar 5 and set transplants outside Apr 23 – May 7, once nights stay above 50°F and the soil is near 60°F. That leaves 192 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.
How long is the growing season in West Valley City?
About 204 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 177 days, and in 1 year in 10 it runs 229 days or more. In fall there is a 10% chance of frost by Oct 17 and a 30% chance by Oct 25. That ranks 3rd longest of 11 Utah cities on this site.
When should I plant a fall garden in West Valley City?
Count back from the first fall frost (Oct 25): transplant broccoli Aug 2 – Aug 16; sow kale Aug 16 – Sep 13; sow lettuce Aug 16 – Sep 13; sow radishes Sep 13 – Oct 11. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 10. How the math works: succession and fall planting.
Did West Valley City's hardiness zone change on the 2023 map?
Yes. Most of West Valley City was zone 7a on the 2012 map and is zone 7b on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.
How does West Valley City compare with West Jordan, UT?
Both are in zone 7b. The typical last spring frost in West Valley City (Apr 16) comes about 9 days earlier than in West Jordan, UT (Apr 25), 6 miles away, and the first fall frost is Oct 25 versus Oct 16. West Valley City sits about 321 ft lower, which explains part of the gap. The two cities use different NOAA stations.