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

Planting zone for 84660 — Spanish Fork, UT

ZIP code 84660 (Spanish Fork, Utah County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 25 and the first fall frost October 18.

Where ZIP 84660 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 frostApr 25

First frostOct 18

2012 zone6b

Was 6b on the 2012 map — half a zone colder 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 Spanish Fork, 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 Spanish Fork, UT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 25median — 50% chance of a later frost

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

First fall frostOctober 18median — 10% chance by Oct 4

Growing season174 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 9 and returns around October 30.

From the NOAA station Spanish Fk Pwr House, UT — 10 miles away, elevation 4,721 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 84660

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 14 – Mar 28

SpinachSow outdoors · Mar 14 – Apr 4

Broccoli, cabbageStart indoors · Feb 14 – Feb 28

Broccoli, cabbageTransplant · Apr 4 – Apr 18

Onion setsPlant outdoors · Mar 28 – Apr 11

PotatoesPlant outdoors · Apr 4 – Apr 18

LettuceSow outdoors · Mar 28 – Apr 11

Carrots, beetsSow outdoors · Apr 4 – Apr 18

TomatoesStart indoors · Feb 28 – Mar 14

TomatoesTransplant · May 2 – May 16

Peppers, eggplantStart indoors · Feb 14 – Feb 28

Peppers, eggplantTransplant · May 9 – May 23

BeansSow outdoors · May 2 – May 16

Sweet cornSow outdoors · May 2 – May 16

Cucumbers, squashSow outdoors · May 2 – May 16

Fall lettuce, spinachSow outdoors · Aug 23 – Sep 6

GarlicPlant cloves · Oct 4 – Nov 8

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 25) and first fall frost (Oct 18) 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 84660 came on Mar 24 — 18 days earlier than the 1991–2020 average (Apr 11).

average
Apr 112026
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.

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 Spanish Fork, UT.

Soil in Spanish Fork, UT

The center of ZIP 84660 is mapped as No Digital Data Available: built-over ground without natural soil data. Garden soil here is usually imported or disturbed — test before you plant.

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 84660; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Spanish Fork, UT

Summer high93 °Faverage high, July

Winter low22 °Faverage low, January

Hot days60days a year at 90 °F or more

Freezing nights118nights a year at 32 °F or less

Growing degree days3,347base 50 °F — the season’s usable heat

Longest day15 h 01 mindaylight on June 21

Shortest day9 h 19 mindaylight on December 21

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

Precipitation20.2 inper year, rain and melted snow

Snowfall66 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: Spanish Fk Pwr House, UT (10 mi away); precipitation: Spanish Fk Pwr House, UT (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

846647a

Mapleton, UT · 10 mi

846636b

Springville, UT · 11 mi

Utah planting zones →

Questions about 84660

What planting zone is ZIP code 84660?

ZIP code 84660 (Spanish Fork, 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 Spanish Fork, UT?

The median last spring frost (32 °F) near 84660 is April 25; after May 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Spanish Fk Pwr House station.

When is the first frost in Spanish Fork, UT?

The median first fall frost near 84660 is October 18, giving a median frost-free growing season of 174 days.

When should I plant tomatoes in 84660?

Start tomato seeds indoors around Feb 28 – Mar 14 and set transplants outside around May 2 – May 16, one to three weeks after the median last frost.

How much rain and snow does 84660 get?

About 20.2 inches of precipitation a year and 66 inches of snowfall (NOAA 1991–2020 normals, Spanish Fk Pwr House station).

How hot do summers get in Spanish Fork, UT?

The average high peaks at 93 °F in July, with about 60 days a year at 90 °F or more.

Did spring come early in Spanish Fork, UT in 2026?

Spring leaf-out near 84660 came on Mar 24 in 2026, 18 days earlier than the 1991–2020 average (Apr 11), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Spanish Fork, UT?

Long-day onions: the longest day near 84660 is 15 h 01 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 84660 change?

Yes. The 2012 USDA map put 84660 in zone 6b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.