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

Planting zone for 53570 — Monticello, WI

ZIP code 53570 (Monticello, Green County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 27 and the first fall frost October 14.

Where ZIP 53570 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostApr 27
First frostOct 14
2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Monticello, WI…

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, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 27median — 50% chance of a later frost
Safe for tender plantsMay 12only 10% chance of frost after
First fall frostOctober 14median — 10% chance by Sep 29
Growing season170 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 15 and returns around October 25.

From the NOAA station Monroe Wwtp, WI — 9 miles away, elevation 991 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 53570

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 16 – Mar 30
SpinachSow outdoors · Mar 16 – Apr 6
Broccoli, cabbageStart indoors · Feb 16 – Mar 2
Broccoli, cabbageTransplant · Apr 6 – Apr 20
Onion setsPlant outdoors · Mar 30 – Apr 13
PotatoesPlant outdoors · Apr 6 – Apr 20
LettuceSow outdoors · Mar 30 – Apr 13
Carrots, beetsSow outdoors · Apr 6 – Apr 20
TomatoesStart indoors · Mar 2 – Mar 16
TomatoesTransplant · May 4 – May 18
Peppers, eggplantStart indoors · Feb 16 – Mar 2
Peppers, eggplantTransplant · May 11 – May 25
BeansSow outdoors · May 4 – May 18
Sweet cornSow outdoors · May 4 – May 18
Cucumbers, squashSow outdoors · May 4 – May 18
Fall lettuce, spinachSow outdoors · Aug 19 – Sep 2
GarlicPlant cloves · Sep 30 – Nov 4
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 27) and first fall frost (Oct 14) 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 53570 came on Mar 30 — 13 days earlier than the 1991–2020 average (Apr 12).

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 5a in Wisconsin

510 plants native to the lower 48 states, recorded in Wisconsin, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 48

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 93

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °F

Wildflowers & perennials 191

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 158

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 5

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °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, WI.

Soil in Monticello, WI

The soil mapped at the center of ZIP 53570 is Newglarus — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH6.7neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Newglarus silt loam, moderately deep, 12 to 20 percent slopes, moderately eroded.

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 53570; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Monticello, WI

Summer high83 °Faverage high, July
Winter low11 °Faverage low, January
Hot days16days a year at 90 °F or more
Freezing nights150nights a year at 32 °F or less
Growing degree days2,802base 50 °F — the season’s usable heat
Longest day15 h 20 mindaylight on June 21
Shortest day9 h 02 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation38.7 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 27 °F, low 11 °F 27°11° JanFebruary: average high 31 °F, low 14 °F 31°14° FebMarch: average high 44 °F, low 25 °F 44°25° MarApril: average high 57 °F, low 37 °F 57°37° AprMay: average high 70 °F, low 49 °F 70°49° MayJune: average high 79 °F, low 59 °F 79°59° JunJuly: average high 83 °F, low 63 °F 83°63° JulAugust: average high 80 °F, low 61 °F 80°61° AugSeptember: average high 73 °F, low 52 °F 73°52° SepOctober: average high 59 °F, low 40 °F 59°40° OctNovember: average high 45 °F, low 29 °F 45°29° NovDecember: average high 32 °F, low 18 °F 32°18° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 1.61 in precipitation 1.6 JanFebruary: 1.72 in precipitation 1.7 FebMarch: 2.05 in precipitation 2.0 MarApril: 3.74 in precipitation 3.7 AprMay: 4.05 in precipitation 4.0 MayJune: 5.52 in precipitation 5.5 JunJuly: 4.12 in precipitation 4.1 JulAugust: 4.31 in precipitation 4.3 AugSeptember: 4.08 in precipitation 4.1 SepOctober: 3.11 in precipitation 3.1 OctNovember: 2.46 in precipitation 2.5 NovDecember: 1.89 in precipitation 1.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Monroe Wwtp, WI (9 mi away); precipitation: Monticello 2.2 Se, WI (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

535745a
New Glarus, WI · 6 mi
535665a
Monroe, WI · 9 mi
535025a
Albany, WI · 9 mi
535085a
Belleville, WI · 10 mi
535045a
Argyle, WI · 12 mi
535215b
Brooklyn, WI · 13 mi
535995a
Woodford, WI · 13 mi
535165a
Blanchardville, WI · 14 mi

Wisconsin planting zones →

Questions about 53570

What planting zone is ZIP code 53570?

ZIP code 53570 (Monticello, WI) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Monticello, WI?

The median last spring frost (32 °F) near 53570 is April 27; after May 12 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Monroe Wwtp station.

When is the first frost in Monticello, WI?

The median first fall frost near 53570 is October 14, giving a median frost-free growing season of 170 days.

When should I plant tomatoes in 53570?

Start tomato seeds indoors around Mar 2 – Mar 16 and set transplants outside around May 4 – May 18, one to three weeks after the median last frost.

How much rain and snow does 53570 get?

About 38.7 inches of precipitation a year (NOAA 1991–2020 normals, Monticello 2.2 Se station).

How hot do summers get in Monticello, WI?

The average high peaks at 83 °F in July, with about 16 days a year at 90 °F or more.

What kind of soil does 53570 have?

The USDA soil survey maps Newglarus at the center of ZIP 53570: silt loam, well drained, pH about 6.7 (neutral).

Did spring come early in Monticello, WI in 2026?

Spring leaf-out near 53570 came on Mar 30 in 2026, 13 days earlier than the 1991–2020 average (Apr 12), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Monticello, WI?

Long-day onions: the longest day near 53570 is 15 h 20 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).