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

Planting zone for 84526 — Helper, UT

ZIP code 84526 (Helper, Carbon County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is June 15 and the first fall frost September 12.

Where ZIP 84526 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 frostJun 15

First frostSep 12

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 Helper, 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 Helper, UT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostJune 15median — 50% chance of a later frost

Safe for tender plantsJuly 1only 10% chance of frost after

First fall frostSeptember 12median — 10% chance by Aug 29

Growing season87 daysfrost-free, median

A hard freeze (28 °F) usually ends around June 3 and returns around September 21.

From the NOAA station Scofield Dam, UT — 11 miles away, elevation 7,632 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 84526

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · May 4 – May 18

SpinachSow outdoors · May 4 – May 25

Broccoli, cabbageStart indoors · Apr 6 – Apr 20

Broccoli, cabbageTransplant · May 25 – Jun 8

Onion setsPlant outdoors · May 18 – Jun 1

PotatoesPlant outdoors · May 25 – Jun 8

LettuceSow outdoors · May 18 – Jun 1

Carrots, beetsSow outdoors · May 25 – Jun 8

TomatoesStart indoors · Apr 20 – May 4

TomatoesTransplant · Jun 22 – Jul 6

Peppers, eggplantStart indoors · Apr 6 – Apr 20

Peppers, eggplantTransplant · Jun 29 – Jul 13

BeansSow outdoors · Jun 22 – Jul 6

Sweet cornSow outdoors · Jun 22 – Jul 6

Cucumbers, squashSow outdoors · Jun 22 – Jul 6

Fall lettuce, spinachSow outdoors · Jul 18 – Aug 1

GarlicPlant cloves · Aug 29 – Oct 3

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 15) and first fall frost (Sep 12) 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 84526 came on Mar 22 — 24 days earlier than the 1991–2020 average (Apr 15).

average
Apr 152026
Mar 22

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 Helper, UT.

Soil in Helper, UT

The soil mapped at the center of ZIP 84526 is Travessilla — extremely bouldery loam, well drained.

TextureExtremely bouldery 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 groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Travessilla-Rock outcrop-Gerst complex.

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 84526; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Helper, UT

Summer high78 °Faverage high, July

Winter low4 °Faverage low, January

Hot days1days a year at 90 °F or more

Freezing nights248nights a year at 32 °F or less

Growing degree days1,050base 50 °F — the season’s usable heat

Longest day14 h 59 mindaylight on June 21

Shortest day9 h 21 mindaylight on December 21

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

Precipitation11.8 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: Scofield Dam, UT (11 mi away); precipitation: Price 2.2 W, 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.

845296b

Kenilworth, UT · 10 mi

845016a

Price, UT · 13 mi

845286a

Huntington, UT · 20 mi

845186a

Cleveland, UT · 21 mi

845216a

Elmo, UT · 21 mi

845426a

Wellington, UT · 26 mi

846475b

Mount Pleasant, UT · 26 mi

846295b

Fairview, UT · 27 mi

Utah planting zones →

Questions about 84526

What planting zone is ZIP code 84526?

ZIP code 84526 (Helper, 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 Helper, UT?

The median last spring frost (32 °F) near 84526 is June 15; after July 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Scofield Dam station.

When is the first frost in Helper, UT?

The median first fall frost near 84526 is September 12, giving a median frost-free growing season of 87 days.

When should I plant tomatoes in 84526?

Start tomato seeds indoors around Apr 20 – May 4 and set transplants outside around Jun 22 – Jul 6, one to three weeks after the median last frost.

How much rain and snow does 84526 get?

About 11.8 inches of precipitation a year (NOAA 1991–2020 normals, Price 2.2 W station).

How hot do summers get in Helper, UT?

The average high peaks at 78 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 84526 have?

The USDA soil survey maps Travessilla at the center of ZIP 84526: extremely bouldery loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Helper, UT in 2026?

Spring leaf-out near 84526 came on Mar 22 in 2026, 24 days earlier than the 1991–2020 average (Apr 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Helper, UT?

Intermediate onions: the longest day near 84526 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.