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

Planting zone for 84079 — Vernal, UT

ZIP code 84079 (Vernal, Uintah County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 7 and the first fall frost October 6.

Where ZIP 84079 is

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 7

First frostOct 6

2012 zone5b

Was 5b on the 2012 map — half a zone warmer now. 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 Vernal, 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 Vernal, UT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 7median — 50% chance of a later frost

Safe for tender plantsMay 28only 10% chance of frost after

First fall frostOctober 6median — 10% chance by Sep 23

Growing season150 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 25 and returns around October 18.

From the NOAA station Vernal, UT — within 1 mile, elevation 5,345 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 84079

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 26 – Apr 9

SpinachSow outdoors · Mar 26 – Apr 16

Broccoli, cabbageStart indoors · Feb 26 – Mar 12

Broccoli, cabbageTransplant · Apr 16 – Apr 30

Onion setsPlant outdoors · Apr 9 – Apr 23

PotatoesPlant outdoors · Apr 16 – Apr 30

LettuceSow outdoors · Apr 9 – Apr 23

Carrots, beetsSow outdoors · Apr 16 – Apr 30

TomatoesStart indoors · Mar 12 – Mar 26

TomatoesTransplant · May 14 – May 28

Peppers, eggplantStart indoors · Feb 26 – Mar 12

Peppers, eggplantTransplant · May 21 – Jun 4

BeansSow outdoors · May 14 – May 28

Sweet cornSow outdoors · May 14 – May 28

Cucumbers, squashSow outdoors · May 14 – May 28

Fall lettuce, spinachSow outdoors · Aug 11 – Aug 25

GarlicPlant cloves · Sep 22 – Oct 27

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 7) and first fall frost (Oct 6) 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 84079 came on Mar 20 — 18 days earlier than the 1991–2020 average (Apr 7).

average
Apr 72026
Mar 20

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 Vernal, UT.

Soil in Vernal, UT

The soil mapped at the center of ZIP 84079 is Boreham — loam, well drained.

TextureLoama good balance for most vegetables

pH8.5alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.75%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Boreham loam, 0 to 2 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 84079; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Vernal, UT

Summer high89 °Faverage high, July

Winter low10 °Faverage low, January

Hot days34days a year at 90 °F or more

Freezing nights174nights a year at 32 °F or less

Growing degree days2,514base 50 °F — the season’s usable heat

Longest day15 h 04 mindaylight on June 21

Shortest day9 h 17 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation9.1 inper year, rain and melted snow

Snowfall20 inper year; 61 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: Vernal, UT (within 1 mile); precipitation: Vernal, UT (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

Fort Duchesne, UT · 20 mi

840856a

Whiterocks, UT · 22 mi

840536a

Neola, UT · 24 mi

All 2 ZIP codes in Vernal → · Utah planting zones →

Questions about 84079

What planting zone is ZIP code 84079?

ZIP code 84079 (Vernal, 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 Vernal, UT?

The median last spring frost (32 °F) near 84079 is May 7; after May 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Vernal station.

When is the first frost in Vernal, UT?

The median first fall frost near 84079 is October 6, giving a median frost-free growing season of 150 days.

When should I plant tomatoes in 84079?

Start tomato seeds indoors around Mar 12 – Mar 26 and set transplants outside around May 14 – May 28, one to three weeks after the median last frost.

How much rain and snow does 84079 get?

About 9.1 inches of precipitation a year and 20 inches of snowfall (NOAA 1991–2020 normals, Vernal station).

How hot do summers get in Vernal, UT?

The average high peaks at 89 °F in July, with about 34 days a year at 90 °F or more.

What kind of soil does 84079 have?

The USDA soil survey maps Boreham at the center of ZIP 84079: loam, well drained, pH about 8.5 (alkaline).

Did spring come early in Vernal, UT in 2026?

Spring leaf-out near 84079 came on Mar 20 in 2026, 18 days earlier than the 1991–2020 average (Apr 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Vernal, UT?

Long-day onions: the longest day near 84079 is 15 h 04 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 84079 change?

Yes. The 2012 USDA map put 84079 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.