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

Planting zone for 84620 — Aurora, UT

ZIP code 84620 (Aurora, Sevier County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 21 and the first fall frost September 24.

Where ZIP 84620 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.

Zone6a−10 to −5 °F

Coldest night−23.3 to −20.6 °C

Last frostMay 21

First frostSep 24

2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Aurora, 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 Aurora, UT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 21median — 50% chance of a later frost

Safe for tender plantsJune 7only 10% chance of frost after

First fall frostSeptember 24median — 10% chance by Sep 12

Growing season125 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 7 and returns around October 4.

From the NOAA station Richfield Radio Ksvc, UT — 14 miles away, elevation 5,286 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 84620

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 9 – Apr 23

SpinachSow outdoors · Apr 9 – Apr 30

Broccoli, cabbageStart indoors · Mar 12 – Mar 26

Broccoli, cabbageTransplant · Apr 30 – May 14

Onion setsPlant outdoors · Apr 23 – May 7

PotatoesPlant outdoors · Apr 30 – May 14

LettuceSow outdoors · Apr 23 – May 7

Carrots, beetsSow outdoors · Apr 30 – May 14

TomatoesStart indoors · Mar 26 – Apr 9

TomatoesTransplant · May 28 – Jun 11

Peppers, eggplantStart indoors · Mar 12 – Mar 26

Peppers, eggplantTransplant · Jun 4 – Jun 18

BeansSow outdoors · May 28 – Jun 11

Sweet cornSow outdoors · May 28 – Jun 11

Cucumbers, squashSow outdoors · May 28 – Jun 11

Fall lettuce, spinachSow outdoors · Jul 30 – Aug 13

GarlicPlant cloves · Sep 10 – Oct 15

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 21) and first fall frost (Sep 24) 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 84620 came on Mar 12 — 15 days earlier than the 1991–2020 average (Mar 27).

average
Mar 272026
Mar 12

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 6a in Utah

546 plants native to the lower 48 states, recorded in Utah, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. 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 Aurora, UT.

Soil in Aurora, UT

The soil mapped at the center of ZIP 84620 is Redfield — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH8.2alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Redfield silt loam, 1 to 3 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 84620; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Aurora, UT

Summer high90 °Faverage high, July

Winter low16 °Faverage low, December

Hot days44days a year at 90 °F or more

Freezing nights176nights a year at 32 °F or less

Growing degree days2,528base 50 °F — the season’s usable heat

Longest day14 h 54 mindaylight on June 21

Shortest day9 h 26 mindaylight on December 21

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

Precipitation7.8 inper year, rain and melted snow

Snowfall18 inper year; 23 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Richfield Radio Ksvc, UT (14 mi away); precipitation: Richfield Radio Ksvc, UT (14 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

Centerfield, UT · 14 mi

Annabella, UT · 15 mi

846346a

Gunnison, UT · 18 mi

Utah planting zones →

Questions about 84620

What planting zone is ZIP code 84620?

ZIP code 84620 (Aurora, UT) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Aurora, UT?

The median last spring frost (32 °F) near 84620 is May 21; after June 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Richfield Radio Ksvc station.

When is the first frost in Aurora, UT?

The median first fall frost near 84620 is September 24, giving a median frost-free growing season of 125 days.

When should I plant tomatoes in 84620?

Start tomato seeds indoors around Mar 26 – Apr 9 and set transplants outside around May 28 – Jun 11, one to three weeks after the median last frost.

How much rain and snow does 84620 get?

About 7.8 inches of precipitation a year and 18 inches of snowfall (NOAA 1991–2020 normals, Richfield Radio Ksvc station).

How hot do summers get in Aurora, UT?

The average high peaks at 90 °F in July, with about 44 days a year at 90 °F or more.

What kind of soil does 84620 have?

The USDA soil survey maps Redfield at the center of ZIP 84620: silt loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Aurora, UT in 2026?

Spring leaf-out near 84620 came on Mar 12 in 2026, 15 days earlier than the 1991–2020 average (Mar 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Aurora, UT?

Intermediate onions: the longest day near 84620 is 14 h 54 min, so day-neutral types bulb best; long-day varieties may not bulb fully.