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

Planting zone for 84624 — Delta, UT

ZIP code 84624 (Delta, Millard County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 16 and the first fall frost September 29.

Where ZIP 84624 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 16
First frostSep 29
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 Delta, 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 Delta, UT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 16median — 50% chance of a later frost
Safe for tender plantsJune 5only 10% chance of frost after
First fall frostSeptember 29median — 10% chance by Sep 16
Growing season137 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 2 and returns around October 9.

From the NOAA station Delta, UT — 3 miles away, elevation 4,620 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 84624

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 4 – Apr 18
SpinachSow outdoors · Apr 4 – Apr 25
Broccoli, cabbageStart indoors · Mar 7 – Mar 21
Broccoli, cabbageTransplant · Apr 25 – May 9
Onion setsPlant outdoors · Apr 18 – May 2
PotatoesPlant outdoors · Apr 25 – May 9
LettuceSow outdoors · Apr 18 – May 2
Carrots, beetsSow outdoors · Apr 25 – May 9
TomatoesStart indoors · Mar 21 – Apr 4
TomatoesTransplant · May 23 – Jun 6
Peppers, eggplantStart indoors · Mar 7 – Mar 21
Peppers, eggplantTransplant · May 30 – Jun 13
BeansSow outdoors · May 23 – Jun 6
Sweet cornSow outdoors · May 23 – Jun 6
Cucumbers, squashSow outdoors · May 23 – Jun 6
Fall lettuce, spinachSow outdoors · Aug 4 – Aug 18
GarlicPlant cloves · Sep 15 – Oct 20
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 16) and first fall frost (Sep 29) 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 84624 came on Mar 7 — 17 days earlier than the 1991–2020 average (Mar 24).

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.

Trees 30

American beech80 ft · blooms mid spring · low shade tolerance · to −44 °FArizona cypress50 ft · blooms spring · low shade tolerance · to −23 °FArizona walnut50 ft · blooms late spring · high shade tolerance · to −33 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fblack walnut100 ft · blooms late spring · high shade tolerance · to −28 °F

Shrubs 107

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °Falderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °FApache plume6 ft · blooms late spring · high shade tolerance · to −23 °F

Wildflowers & perennials 248

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °F

Grasses 151

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAlpine Meadow-Foxtail0.5 ft · blooms mid spring · medium shade tolerance · to −33 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Fanalogue sedge1.5 ft · blooms late spring · medium shade tolerance · to −38 °Farctic bluegrass2 ft · high shade tolerance · to −62 °F

Vines 3

trumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °Fwestern white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °F

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 Delta, UT.

Soil in Delta, UT

The soil mapped at the center of ZIP 84624 is Abbott — silty clay, poorly drained.

TextureSilty clayholds water and nutrients; slow to drain and warm up
pH8.8alkaline; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter1.5%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Abbott silty clay, strongly saline.

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 84624; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Delta, UT

Summer high95 °Faverage high, July
Winter low15 °Faverage low, December
Hot days74days a year at 90 °F or more
Freezing nights176nights a year at 32 °F or less
Growing degree days3,015base 50 °F — the season’s usable heat
Longest day14 h 57 mindaylight on June 21
Shortest day9 h 23 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation8 inper year, rain and melted snow
Snowfall25 inper year

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°110°32 °FJanuary: average high 39 °F, low 16 °F 39°16° JanFebruary: average high 47 °F, low 21 °F 47°21° FebMarch: average high 58 °F, low 27 °F 58°27° MarApril: average high 65 °F, low 33 °F 65°33° AprMay: average high 76 °F, low 41 °F 76°41° MayJune: average high 87 °F, low 49 °F 87°49° JunJuly: average high 95 °F, low 57 °F 95°57° JulAugust: average high 93 °F, low 56 °F 93°56° AugSeptember: average high 82 °F, low 46 °F 82°46° SepOctober: average high 68 °F, low 33 °F 68°33° OctNovember: average high 51 °F, low 23 °F 51°23° NovDecember: average high 39 °F, low 15 °F 39°15° Dec

Precipitation by month inches · ❄ = snowfall

0″1″January: 0.63 in precipitation, 5.5 in snowfall 0.6❄6 JanFebruary: 0.64 in precipitation, 5.3 in snowfall 0.6❄5 FebMarch: 0.80 in precipitation, 3.9 in snowfall 0.8❄4 MarApril: 0.94 in precipitation, 2.2 in snowfall 0.9❄2 AprMay: 0.92 in precipitation 0.9 MayJune: 0.48 in precipitation 0.5 JunJuly: 0.35 in precipitation 0.3 JulAugust: 0.54 in precipitation 0.5 AugSeptember: 0.71 in precipitation 0.7 SepOctober: 0.91 in precipitation, 0.8 in snowfall 0.9❄1 OctNovember: 0.50 in precipitation, 3.2 in snowfall 0.5❄3 NovDecember: 0.59 in precipitation, 4.4 in snowfall 0.6❄4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Delta, UT (3 mi away); precipitation: Delta, UT (3 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.

846356a
Hinckley, UT · 7 mi
846406a
Lynndyl, UT · 12 mi
846496b
Oak City, UT · 14 mi
846386a
Leamington, UT · 20 mi
846366a
Holden, UT · 22 mi
846565b
Scipio, UT · 28 mi
846316a
Fillmore, UT · 29 mi
846446b
Meadow, UT · 39 mi

Utah planting zones →

Questions about 84624

What planting zone is ZIP code 84624?

ZIP code 84624 (Delta, 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 Delta, UT?

The median last spring frost (32 °F) near 84624 is May 16; after June 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Delta station.

When is the first frost in Delta, UT?

The median first fall frost near 84624 is September 29, giving a median frost-free growing season of 137 days.

When should I plant tomatoes in 84624?

Start tomato seeds indoors around Mar 21 – Apr 4 and set transplants outside around May 23 – Jun 6, one to three weeks after the median last frost.

How much rain and snow does 84624 get?

About 8 inches of precipitation a year and 25 inches of snowfall (NOAA 1991–2020 normals, Delta station).

How hot do summers get in Delta, UT?

The average high peaks at 95 °F in July, with about 74 days a year at 90 °F or more.

What kind of soil does 84624 have?

The USDA soil survey maps Abbott at the center of ZIP 84624: silty clay, poorly drained, pH about 8.8 (alkaline).

Did spring come early in Delta, UT in 2026?

Spring leaf-out near 84624 came on Mar 7 in 2026, 17 days earlier than the 1991–2020 average (Mar 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Delta, UT?

Intermediate onions: the longest day near 84624 is 14 h 57 min, so day-neutral types bulb best; long-day varieties may not bulb fully.