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

Planting zone for 84535 — Monticello, UT

ZIP code 84535 (Monticello, San Juan County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is May 19 and the first fall frost October 2.

Where ZIP 84535 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.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostMay 19
First frostOct 2
2012 zone6a

Was 6a 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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Monticello, 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 Monticello, UT

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 19median — 50% chance of a later frost
Safe for tender plantsJune 6only 10% chance of frost after
First fall frostOctober 2median — 10% chance by Sep 20
Growing season133 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 6 and returns around October 12.

From the NOAA station Monticello 2e, UT — 2 miles away, elevation 6,821 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 84535

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 7 – Apr 21
SpinachSow outdoors · Apr 7 – Apr 28
Broccoli, cabbageStart indoors · Mar 10 – Mar 24
Broccoli, cabbageTransplant · Apr 28 – May 12
Onion setsPlant outdoors · Apr 21 – May 5
PotatoesPlant outdoors · Apr 28 – May 12
LettuceSow outdoors · Apr 21 – May 5
Carrots, beetsSow outdoors · Apr 28 – May 12
TomatoesStart indoors · Mar 24 – Apr 7
TomatoesTransplant · May 26 – Jun 9
Peppers, eggplantStart indoors · Mar 10 – Mar 24
Peppers, eggplantTransplant · Jun 2 – Jun 16
BeansSow outdoors · May 26 – Jun 9
Sweet cornSow outdoors · May 26 – Jun 9
Cucumbers, squashSow outdoors · May 26 – Jun 9
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 19) 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 84535 came on Mar 17 — 19 days earlier than the 1991–2020 average (Apr 5).

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 6b in Utah

549 plants native to the lower 48 states, recorded in Utah, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 251

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 Monticello, UT.

Soil in Monticello, UT

The soil mapped at the center of ZIP 84535 is Monticello — very fine sandy loam, well drained.

TextureVery fine sandy loamdrains and warms fast; dries out and needs more feeding
pH7.0neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupBwater soaks in moderately
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Monticello very fine sandy loam, 0 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 84535; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Monticello, UT

Summer high85 °Faverage high, July
Winter low15 °Faverage low, January
Hot days8days a year at 90 °F or more
Freezing nights180nights a year at 32 °F or less
Growing degree days2,116base 50 °F — the season’s usable heat
Longest day14 h 47 mindaylight on June 21
Shortest day9 h 32 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation15.1 inper year, rain and melted snow
Snowfall64 inper year; 58 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 36 °F, low 15 °F 36°15° JanFebruary: average high 41 °F, low 20 °F 41°20° FebMarch: average high 50 °F, low 26 °F 50°26° MarApril: average high 59 °F, low 31 °F 59°31° AprMay: average high 69 °F, low 39 °F 69°39° MayJune: average high 81 °F, low 47 °F 81°47° JunJuly: average high 85 °F, low 54 °F 85°54° JulAugust: average high 82 °F, low 53 °F 82°53° AugSeptember: average high 75 °F, low 45 °F 75°45° SepOctober: average high 62 °F, low 34 °F 62°34° OctNovember: average high 48 °F, low 24 °F 48°24° NovDecember: average high 36 °F, low 16 °F 36°16° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″January: 1.57 in precipitation, 13.4 in snowfall 1.6❄13 JanFebruary: 1.48 in precipitation, 13.5 in snowfall 1.5❄14 FebMarch: 1.09 in precipitation, 7.4 in snowfall 1.1❄7 MarApril: 0.88 in precipitation, 6.1 in snowfall 0.9❄6 AprMay: 0.89 in precipitation, 1.1 in snowfall 0.9❄1 MayJune: 0.51 in precipitation, 0.1 in snowfall 0.5 JunJuly: 1.36 in precipitation 1.4 JulAugust: 1.80 in precipitation 1.8 AugSeptember: 1.67 in precipitation, 0.1 in snowfall 1.7 SepOctober: 1.32 in precipitation, 1.3 in snowfall 1.3❄1 OctNovember: 1.19 in precipitation, 7.3 in snowfall 1.2❄7 NovDecember: 1.34 in precipitation, 13.9 in snowfall 1.3❄14 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Monticello 2e, UT (2 mi away); precipitation: Monticello 2e, UT (2 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.

813246b
Dove Creek, CO · 21 mi
845117a
Blanding, UT · 23 mi
845307a
La Sal, UT · 28 mi
813206b
Cahone, CO · 32 mi
813256b
Egnar, CO · 32 mi
814116b
Bedrock, CO · 33 mi
813316b
Pleasant View, CO · 35 mi
813356b
Yellow Jacket, CO · 38 mi

Utah planting zones →

Questions about 84535

What planting zone is ZIP code 84535?

ZIP code 84535 (Monticello, UT) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Monticello, UT?

The median last spring frost (32 °F) near 84535 is May 19; after June 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Monticello 2e station.

When is the first frost in Monticello, UT?

The median first fall frost near 84535 is October 2, giving a median frost-free growing season of 133 days.

When should I plant tomatoes in 84535?

Start tomato seeds indoors around Mar 24 – Apr 7 and set transplants outside around May 26 – Jun 9, one to three weeks after the median last frost.

How much rain and snow does 84535 get?

About 15.1 inches of precipitation a year and 64 inches of snowfall (NOAA 1991–2020 normals, Monticello 2e station).

How hot do summers get in Monticello, UT?

The average high peaks at 85 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 84535 have?

The USDA soil survey maps Monticello at the center of ZIP 84535: very fine sandy loam, well drained, pH about 7.0 (neutral).

Did spring come early in Monticello, UT in 2026?

Spring leaf-out near 84535 came on Mar 17 in 2026, 19 days earlier than the 1991–2020 average (Apr 5), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Monticello, UT?

Intermediate onions: the longest day near 84535 is 14 h 47 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 84535 change?

Yes. The 2012 USDA map put 84535 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.