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

Planting zone for 84325 — Mendon, UT

ZIP code 84325 (Mendon, Cache County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 8 and the first fall frost October 2.

Where ZIP 84325 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 8

First frostOct 2

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 Mendon, 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 Mendon, UT

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 8median — 50% chance of a later frost

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

First fall frostOctober 2median — 10% chance by Sep 18

Growing season145 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 23 and returns around October 14.

From the NOAA station Logan Radio Kvnu, UT — 7 miles away, elevation 4,475 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 84325

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 27 – Apr 10

SpinachSow outdoors · Mar 27 – Apr 17

Broccoli, cabbageStart indoors · Feb 27 – Mar 13

Broccoli, cabbageTransplant · Apr 17 – May 1

Onion setsPlant outdoors · Apr 10 – Apr 24

PotatoesPlant outdoors · Apr 17 – May 1

LettuceSow outdoors · Apr 10 – Apr 24

Carrots, beetsSow outdoors · Apr 17 – May 1

TomatoesStart indoors · Mar 13 – Mar 27

TomatoesTransplant · May 15 – May 29

Peppers, eggplantStart indoors · Feb 27 – Mar 13

Peppers, eggplantTransplant · May 22 – Jun 5

BeansSow outdoors · May 15 – May 29

Sweet cornSow outdoors · May 15 – May 29

Cucumbers, squashSow outdoors · May 15 – May 29

Fall lettuce, spinachSow outdoors · Aug 7 – Aug 21

GarlicPlant cloves · Sep 18 – Oct 23

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 8) and first fall frost (Oct 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 84325 came on Mar 19 — 20 days earlier than the 1991–2020 average (Apr 8).

average
Apr 82026
Mar 19

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 Mendon, UT.

Soil in Mendon, UT

The soil mapped at the center of ZIP 84325 is Avon — silty clay loam, well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up

pH7.0neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter4%moderate

Hydrologic groupCwater soaks in slowly

Farmland classPrime farmland if irrigatedUSDA classification

Map unit: AVON SILTY CLAY LOAM, 3 TO 6 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 84325; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mendon, UT

Summer high89 °Faverage high, July

Winter low14 °Faverage low, January

Hot days35days a year at 90 °F or more

Freezing nights166nights a year at 32 °F or less

Growing degree days2,381base 50 °F — the season’s usable heat

Longest day15 h 13 mindaylight on June 21

Shortest day9 h 08 mindaylight on December 21

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

Precipitation16.6 inper year, rain and melted snow

Snowfall44 inper year; 73 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: Logan Radio Kvnu, UT (7 mi away); precipitation: Logan Radio Kvnu, UT (7 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.

843066a

Collinston, UT · 4 mi

843096b

Deweyville, UT · 5 mi

843046a

Cache Junction, UT · 6 mi

843146b

Honeyville, UT · 8 mi

843116a

Fielding, UT · 8 mi

843396a

Wellsville, UT · 8 mi

843356a

Smithfield, UT · 8 mi

843236a

Logan, UT · 8 mi

Utah planting zones →

Questions about 84325

What planting zone is ZIP code 84325?

ZIP code 84325 (Mendon, 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 Mendon, UT?

The median last spring frost (32 °F) near 84325 is May 8; after June 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Logan Radio Kvnu station.

When is the first frost in Mendon, UT?

The median first fall frost near 84325 is October 2, giving a median frost-free growing season of 145 days.

When should I plant tomatoes in 84325?

Start tomato seeds indoors around Mar 13 – Mar 27 and set transplants outside around May 15 – May 29, one to three weeks after the median last frost.

How much rain and snow does 84325 get?

About 16.6 inches of precipitation a year and 44 inches of snowfall (NOAA 1991–2020 normals, Logan Radio Kvnu station).

How hot do summers get in Mendon, UT?

The average high peaks at 89 °F in July, with about 35 days a year at 90 °F or more.

What kind of soil does 84325 have?

The USDA soil survey maps Avon at the center of ZIP 84325: silty clay loam, well drained, pH about 7.0 (neutral).

Did spring come early in Mendon, UT in 2026?

Spring leaf-out near 84325 came on Mar 19 in 2026, 20 days earlier than the 1991–2020 average (Apr 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mendon, UT?

Long-day onions: the longest day near 84325 is 15 h 13 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 84325 change?

Yes. The 2012 USDA map put 84325 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.