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

Planting zone for 84763 — Rockville, UT

ZIP code 84763 (Rockville, Washington County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is April 13 and the first fall frost November 2.

Where ZIP 84763 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.

Zone8a10 to 15 °F

Coldest night−12.2 to −9.4 °C

Last frostApr 13

First frostNov 2

2012 zone8a

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 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Rockville, 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 Rockville, UT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 13median — 50% chance of a later frost

Safe for tender plantsMay 2only 10% chance of frost after

First fall frostNovember 2median — 10% chance by Oct 20

Growing season202 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 23 and returns around November 12.

From the NOAA station Zion Np, UT — 6 miles away, elevation 4,039 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 84763

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 2 – Mar 16

SpinachSow outdoors · Mar 2 – Mar 23

Broccoli, cabbageStart indoors · Feb 2 – Feb 16

Broccoli, cabbageTransplant · Mar 23 – Apr 6

Onion setsPlant outdoors · Mar 16 – Mar 30

PotatoesPlant outdoors · Mar 23 – Apr 6

LettuceSow outdoors · Mar 16 – Mar 30

Carrots, beetsSow outdoors · Mar 23 – Apr 6

TomatoesStart indoors · Feb 16 – Mar 2

TomatoesTransplant · Apr 20 – May 4

Peppers, eggplantStart indoors · Feb 2 – Feb 16

Peppers, eggplantTransplant · Apr 27 – May 11

BeansSow outdoors · Apr 20 – May 4

Sweet cornSow outdoors · Apr 20 – May 4

Cucumbers, squashSow outdoors · Apr 20 – May 4

Fall lettuce, spinachSow outdoors · Sep 7 – Sep 21

GarlicPlant cloves · Oct 19 – Nov 23

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 13) and first fall frost (Nov 2) 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 84763 came on Feb 6 — 11 days earlier than the 1991–2020 average (Feb 17).

average
Feb 172026
Feb 6

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 8a in Utah

575 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 8a. 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 Rockville, UT.

Soil in Rockville, UT

The soil mapped at the center of ZIP 84763 is Bond — sandy loam, well drained.

TextureSandy 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 matter1.5%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Bond sandy loam, 1 to 10 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 84763; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Rockville, UT

Summer high100 °Faverage high, July

Winter low29 °Faverage low, December

Hot days119days a year at 90 °F or more

Freezing nights71nights a year at 32 °F or less

Growing degree days5,324base 50 °F — the season’s usable heat

Longest day14 h 43 mindaylight on June 21

Shortest day9 h 36 mindaylight on December 21

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

Precipitation16.3 inper year, rain and melted snow

Snowfall4 inper year; 2 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: Zion Np, UT (6 mi away); precipitation: Zion Np, UT (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

847676b

Springdale, UT · 6 mi

847847a

Hildale, UT · 10 mi

847458a

La Verkin, UT · 11 mi

847378b

Hurricane, UT · 13 mi

847796b

Virgin, UT · 13 mi

847748b

Toquerville, UT · 13 mi

860217b

Colorado City, AZ · 15 mi

847557a

Mount Carmel, UT · 17 mi

Utah planting zones →

Questions about 84763

What planting zone is ZIP code 84763?

ZIP code 84763 (Rockville, UT) is in USDA hardiness zone 8a on the 2023 map: the coldest night of an average winter reaches 10 to 15 °F (−12.2 to −9.4 °C).

When is the last frost in Rockville, UT?

The median last spring frost (32 °F) near 84763 is April 13; after May 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Zion Np station.

When is the first frost in Rockville, UT?

The median first fall frost near 84763 is November 2, giving a median frost-free growing season of 202 days.

When should I plant tomatoes in 84763?

Start tomato seeds indoors around Feb 16 – Mar 2 and set transplants outside around Apr 20 – May 4, one to three weeks after the median last frost.

How much rain and snow does 84763 get?

About 16.3 inches of precipitation a year and 4 inches of snowfall (NOAA 1991–2020 normals, Zion Np station).

How hot do summers get in Rockville, UT?

The average high peaks at 100 °F in July, with about 119 days a year at 90 °F or more.

What kind of soil does 84763 have?

The USDA soil survey maps Bond at the center of ZIP 84763: sandy loam, well drained, pH about 7.6 (slightly alkaline).

Did spring come early in Rockville, UT in 2026?

Spring leaf-out near 84763 came on Feb 6 in 2026, 11 days earlier than the 1991–2020 average (Feb 17), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Rockville, UT?

Intermediate onions: the longest day near 84763 is 14 h 43 min, so day-neutral types bulb best; long-day varieties may not bulb fully.