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

Planting zone for 84740 — Junction, UT

ZIP code 84740 (Junction, Piute County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 23 and the first fall frost September 27.

Where ZIP 84740 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 23

First frostSep 27

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 Junction, 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 Junction, UT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 23median — 50% chance of a later frost

Safe for tender plantsJune 13only 10% chance of frost after

First fall frostSeptember 27median — 10% chance by Sep 12

Growing season125 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 8 and returns around October 5.

From the NOAA station Circleville, UT — 8 miles away, elevation 6,050 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 84740

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 11 – Apr 25

SpinachSow outdoors · Apr 11 – May 2

Broccoli, cabbageStart indoors · Mar 14 – Mar 28

Broccoli, cabbageTransplant · May 2 – May 16

Onion setsPlant outdoors · Apr 25 – May 9

PotatoesPlant outdoors · May 2 – May 16

LettuceSow outdoors · Apr 25 – May 9

Carrots, beetsSow outdoors · May 2 – May 16

TomatoesStart indoors · Mar 28 – Apr 11

TomatoesTransplant · May 30 – Jun 13

Peppers, eggplantStart indoors · Mar 14 – Mar 28

Peppers, eggplantTransplant · Jun 6 – Jun 20

BeansSow outdoors · May 30 – Jun 13

Sweet cornSow outdoors · May 30 – Jun 13

Cucumbers, squashSow outdoors · May 30 – Jun 13

Fall lettuce, spinachSow outdoors · Aug 2 – Aug 16

GarlicPlant cloves · Sep 13 – Oct 18

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 23) and first fall frost (Sep 27) 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 84740 came on Mar 22 — 18 days earlier than the 1991–2020 average (Apr 9).

average
Apr 92026
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 Junction, UT.

Soil in Junction, UT

The soil mapped at the center of ZIP 84740 is Bregar — very gravelly sandy clay loam, well drained.

TextureVery gravelly sandy clay loamholds water and nutrients; slow to drain and warm up

pH8.2alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.5%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Bregar family-Duco family, stony-Rock outcrop complex, 15 to 75 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 84740; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Junction, UT

Summer high90 °Faverage high, July

Winter low16 °Faverage low, January

Hot days35days a year at 90 °F or more

Freezing nights186nights a year at 32 °F or less

Growing degree days2,565base 50 °F — the season’s usable heat

Longest day14 h 50 mindaylight on June 21

Shortest day9 h 30 mindaylight on December 21

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

Precipitation32.7 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: Circleville, UT (8 mi away); precipitation: Big Flat, UT (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

847435b

Kingston, UT · 7 mi

847235b

Circleville, UT · 8 mi

847506a

Marysvale, UT · 11 mi

Utah planting zones →

Questions about 84740

What planting zone is ZIP code 84740?

ZIP code 84740 (Junction, 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 Junction, UT?

The median last spring frost (32 °F) near 84740 is May 23; after June 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Circleville station.

When is the first frost in Junction, UT?

The median first fall frost near 84740 is September 27, giving a median frost-free growing season of 125 days.

When should I plant tomatoes in 84740?

Start tomato seeds indoors around Mar 28 – Apr 11 and set transplants outside around May 30 – Jun 13, one to three weeks after the median last frost.

How much rain and snow does 84740 get?

About 32.7 inches of precipitation a year (NOAA 1991–2020 normals, Big Flat station).

How hot do summers get in Junction, UT?

The average high peaks at 90 °F in July, with about 35 days a year at 90 °F or more.

What kind of soil does 84740 have?

The USDA soil survey maps Bregar at the center of ZIP 84740: very gravelly sandy clay loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Junction, UT in 2026?

Spring leaf-out near 84740 came on Mar 22 in 2026, 18 days earlier than the 1991–2020 average (Apr 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Junction, UT?

Intermediate onions: the longest day near 84740 is 14 h 50 min, so day-neutral types bulb best; long-day varieties may not bulb fully.