Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 84720 — Cedar City, UT

ZIP code 84720 (Cedar City, Iron County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is May 9 and the first fall frost October 11.

Where ZIP 84720 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone6b−5 to 0 °F

Coldest night−20.6 to −17.8 °C

Last frostMay 9

First frostOct 11

2012 zone6b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Cedar City, UT…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Cedar City, UT

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMay 9median — 50% chance of a later frost

Safe for tender plantsMay 29only 10% chance of frost after

First fall frostOctober 11median — 10% chance by Sep 27

Growing season155 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 24 and returns around October 22.

From the NOAA station New Harmony, UT — 9 miles away, elevation 5,168 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 84720

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 28 – Apr 11

SpinachSow outdoors · Mar 28 – Apr 18

Broccoli, cabbageStart indoors · Feb 28 – Mar 14

Broccoli, cabbageTransplant · Apr 18 – May 2

Onion setsPlant outdoors · Apr 11 – Apr 25

PotatoesPlant outdoors · Apr 18 – May 2

LettuceSow outdoors · Apr 11 – Apr 25

Carrots, beetsSow outdoors · Apr 18 – May 2

TomatoesStart indoors · Mar 14 – Mar 28

TomatoesTransplant · May 16 – May 30

Peppers, eggplantStart indoors · Feb 28 – Mar 14

Peppers, eggplantTransplant · May 23 – Jun 6

BeansSow outdoors · May 16 – May 30

Sweet cornSow outdoors · May 16 – May 30

Cucumbers, squashSow outdoors · May 16 – May 30

Fall lettuce, spinachSow outdoors · Aug 16 – Aug 30

GarlicPlant cloves · Sep 27 – Nov 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Oct 11) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 84720 came on Mar 17 — 23 days earlier than the 1991–2020 average (Apr 9).

average
Apr 92026
Mar 17

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 6b in Utah

549 plants native to the lower 48 states, recorded in Utah, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. Each links to its USDA PLANTS profile.

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Cedar City, UT.

Soil in Cedar City, UT

The soil mapped at the center of ZIP 84720 is Tolman — very cobbly loam, well drained.

TextureVery cobbly loama good balance for most vegetables

pH7.6slightly alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter4.5%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Tolman-Dalcan-Rock outcrop complex, 25 to 60 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 84720; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Cedar City, UT

Summer high90 °Faverage high, July

Winter low21 °Faverage low, January

Hot days36days a year at 90 °F or more

Freezing nights148nights a year at 32 °F or less

Growing degree days2,837base 50 °F — the season’s usable heat

Longest day14 h 46 mindaylight on June 21

Shortest day9 h 34 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation21.8 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: New Harmony, UT (9 mi away); precipitation: Long Flat, UT (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

3 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

847577a

New Harmony, UT · 9 mi

847426b

Kanarraville, UT · 9 mi

847216b

Cedar City, UT · 15 mi

847226b

Central, UT · 16 mi

847816b

Pine Valley, UT · 17 mi

847565b

Newcastle, UT · 17 mi

All 2 ZIP codes in Cedar City → · Utah planting zones →

Questions about 84720

What planting zone is ZIP code 84720?

ZIP code 84720 (Cedar City, UT) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Cedar City, UT?

The median last spring frost (32 °F) near 84720 is May 9; after May 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, New Harmony station.

When is the first frost in Cedar City, UT?

The median first fall frost near 84720 is October 11, giving a median frost-free growing season of 155 days.

When should I plant tomatoes in 84720?

Start tomato seeds indoors around Mar 14 – Mar 28 and set transplants outside around May 16 – May 30, one to three weeks after the median last frost.

How much rain and snow does 84720 get?

About 21.8 inches of precipitation a year (NOAA 1991–2020 normals, Long Flat station).

How hot do summers get in Cedar City, UT?

The average high peaks at 90 °F in July, with about 36 days a year at 90 °F or more.

What kind of soil does 84720 have?

The USDA soil survey maps Tolman at the center of ZIP 84720: very cobbly loam, well drained, pH about 7.6 (slightly alkaline).

Did spring come early in Cedar City, UT in 2026?

Spring leaf-out near 84720 came on Mar 17 in 2026, 23 days earlier than the 1991–2020 average (Apr 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Cedar City, UT?

Intermediate onions: the longest day near 84720 is 14 h 46 min, so day-neutral types bulb best; long-day varieties may not bulb fully.