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

Planting zone for 84638 — Leamington, UT

ZIP code 84638 (Leamington, Millard County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 2 and the first fall frost October 13.

Where ZIP 84638 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 2

First frostOct 13

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 Leamington, 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 Leamington, UT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 2median — 50% chance of a later frost

Safe for tender plantsMay 21only 10% chance of frost after

First fall frostOctober 13median — 10% chance by Sep 30

Growing season162 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 20 and returns around October 24.

From the NOAA station Oak City, UT — 9 miles away, elevation 5,095 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 84638

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 21 – Apr 4

SpinachSow outdoors · Mar 21 – Apr 11

Broccoli, cabbageStart indoors · Feb 21 – Mar 7

Broccoli, cabbageTransplant · Apr 11 – Apr 25

Onion setsPlant outdoors · Apr 4 – Apr 18

PotatoesPlant outdoors · Apr 11 – Apr 25

LettuceSow outdoors · Apr 4 – Apr 18

Carrots, beetsSow outdoors · Apr 11 – Apr 25

TomatoesStart indoors · Mar 7 – Mar 21

TomatoesTransplant · May 9 – May 23

Peppers, eggplantStart indoors · Feb 21 – Mar 7

Peppers, eggplantTransplant · May 16 – May 30

BeansSow outdoors · May 9 – May 23

Sweet cornSow outdoors · May 9 – May 23

Cucumbers, squashSow outdoors · May 9 – May 23

Fall lettuce, spinachSow outdoors · Aug 18 – Sep 1

GarlicPlant cloves · Sep 29 – Nov 3

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 2) and first fall frost (Oct 13) 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 84638 came on Mar 1 — 25 days earlier than the 1991–2020 average (Mar 26).

average
Mar 262026
Mar 1

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 Leamington, UT.

Soil in Leamington, UT

The soil mapped at the center of ZIP 84638 is Heist — fine sandy loam, well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding

pH7.6slightly alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.75%low — add compost

Hydrologic groupAwater soaks in fast

Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Heist fine sandy loam, 2 to 5 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 84638; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Leamington, UT

Summer high93 °Faverage high, July

Winter low20 °Faverage low, January

Hot days64days a year at 90 °F or more

Freezing nights134nights a year at 32 °F or less

Growing degree days3,440base 50 °F — the season’s usable heat

Longest day14 h 58 mindaylight on June 21

Shortest day9 h 22 mindaylight on December 21

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

Precipitation13.9 inper year, rain and melted snow

Snowfall33 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Oak City, UT (9 mi away); precipitation: Oak City, UT (9 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.

Utah planting zones →

Questions about 84638

What planting zone is ZIP code 84638?

ZIP code 84638 (Leamington, 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 Leamington, UT?

The median last spring frost (32 °F) near 84638 is May 2; after May 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Oak City station.

When is the first frost in Leamington, UT?

The median first fall frost near 84638 is October 13, giving a median frost-free growing season of 162 days.

When should I plant tomatoes in 84638?

Start tomato seeds indoors around Mar 7 – Mar 21 and set transplants outside around May 9 – May 23, one to three weeks after the median last frost.

How much rain and snow does 84638 get?

About 13.9 inches of precipitation a year and 33 inches of snowfall (NOAA 1991–2020 normals, Oak City station).

How hot do summers get in Leamington, UT?

The average high peaks at 93 °F in July, with about 64 days a year at 90 °F or more.

What kind of soil does 84638 have?

The USDA soil survey maps Heist at the center of ZIP 84638: fine sandy loam, well drained, pH about 7.6 (slightly alkaline).

Did spring come early in Leamington, UT in 2026?

Spring leaf-out near 84638 came on Mar 1 in 2026, 25 days earlier than the 1991–2020 average (Mar 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Leamington, UT?

Intermediate onions: the longest day near 84638 is 14 h 58 min, so day-neutral types bulb best; long-day varieties may not bulb fully.