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

Planting zone for 48471 — Sandusky, MI

ZIP code 48471 (Sandusky, Sanilac County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 2 and the first fall frost October 16.

Where ZIP 48471 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 2
First frostOct 16
2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Sandusky, MI…

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 Sandusky, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 2median — 50% chance of a later frost
Safe for tender plantsMay 17only 10% chance of frost after
First fall frostOctober 16median — 10% chance by Oct 1
Growing season165 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 22 and returns around October 30.

From the NOAA station Sandusky, MI — 2 miles away, elevation 774 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 48471

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 21 – Apr 4
SpinachSow outdoors · Mar 21 – Apr 11
Broccoli, cabbageStart indoors · Feb 21 – Mar 7
Broccoli, cabbageTransplant · Apr 11 – Apr 25
Onion setsPlant outdoors · Apr 4 – Apr 18
PotatoesPlant outdoors · Apr 11 – Apr 25
LettuceSow outdoors · Apr 4 – Apr 18
Carrots, beetsSow outdoors · Apr 11 – Apr 25
TomatoesStart indoors · Mar 7 – Mar 21
TomatoesTransplant · May 9 – May 23
Peppers, eggplantStart indoors · Feb 21 – Mar 7
Peppers, eggplantTransplant · May 16 – May 30
BeansSow outdoors · May 9 – May 23
Sweet cornSow outdoors · May 9 – May 23
Cucumbers, squashSow outdoors · May 9 – May 23
Fall lettuce, spinachSow outdoors · Aug 21 – Sep 4
GarlicPlant cloves · Oct 2 – Nov 6
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 2) and first fall frost (Oct 16) 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 48471 came on Apr 12 — 3 days earlier than the 1991–2020 average (Apr 15).

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 Michigan

580 plants native to the lower 48 states, recorded in Michigan, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.

Trees 58

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 105

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 220

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °F

Grasses 174

alpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °FAmerican 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 °F

Vines 8

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °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 Sandusky, MI.

Soil in Sandusky, MI

The soil mapped at the center of ZIP 48471 is Parkhill — clay loam, poorly drained.

TextureClay loamholds water and nutrients; slow to drain and warm up
pH7.3neutral; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter3%moderate
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Parkhill loam and clay loam, 0 to 2 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 48471; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sandusky, MI

Summer high80 °Faverage high, July
Winter low14 °Faverage low, February
Hot days6days a year at 90 °F or more
Freezing nights151nights a year at 32 °F or less
Growing degree days2,396base 50 °F — the season’s usable heat
Longest day15 h 25 mindaylight on June 21
Shortest day8 h 57 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation31.3 inper year, rain and melted snow
Snowfall41 inper year; 63 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 28 °F, low 15 °F 28°15° JanFebruary: average high 31 °F, low 14 °F 31°14° FebMarch: average high 41 °F, low 24 °F 41°24° MarApril: average high 54 °F, low 33 °F 54°33° AprMay: average high 67 °F, low 45 °F 67°45° MayJune: average high 77 °F, low 56 °F 77°56° JunJuly: average high 80 °F, low 60 °F 80°60° JulAugust: average high 78 °F, low 58 °F 78°58° AugSeptember: average high 72 °F, low 51 °F 72°51° SepOctober: average high 59 °F, low 40 °F 59°40° OctNovember: average high 45 °F, low 30 °F 45°30° NovDecember: average high 34 °F, low 22 °F 34°22° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 1.86 in precipitation, 13 in snowfall 1.9❄13 JanFebruary: 1.62 in precipitation, 9.5 in snowfall 1.6❄10 FebMarch: 1.86 in precipitation, 6.3 in snowfall 1.9❄6 MarApril: 3.04 in precipitation, 2.1 in snowfall 3.0❄2 AprMay: 3.31 in precipitation 3.3 MayJune: 3.29 in precipitation 3.3 JunJuly: 3.06 in precipitation 3.1 JulAugust: 2.97 in precipitation 3.0 AugSeptember: 3.08 in precipitation 3.1 SepOctober: 2.81 in precipitation, 0.2 in snowfall 2.8 OctNovember: 2.40 in precipitation, 2 in snowfall 2.4❄2 NovDecember: 2.03 in precipitation, 7.6 in snowfall 2.0❄8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Sandusky, MI (2 mi away); precipitation: Yale 1 Nnw, MI (19 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

484726a
Snover, MI · 8 mi
484196a
Carsonville, MI · 10 mi
484666a
Peck, MI · 10 mi
484276a
Deckerville, MI · 10 mi
484536a
Marlette, MI · 10 mi
484016a
Applegate, MI · 11 mi
484106a
Argyle, MI · 11 mi
484266a
Decker, MI · 12 mi

Michigan planting zones →

Questions about 48471

What planting zone is ZIP code 48471?

ZIP code 48471 (Sandusky, MI) 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 Sandusky, MI?

The median last spring frost (32 °F) near 48471 is May 2; after May 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Sandusky station.

When is the first frost in Sandusky, MI?

The median first fall frost near 48471 is October 16, giving a median frost-free growing season of 165 days.

When should I plant tomatoes in 48471?

Start tomato seeds indoors around Mar 7 – Mar 21 and set transplants outside around May 9 – May 23, one to three weeks after the median last frost.

How much rain and snow does 48471 get?

About 31.3 inches of precipitation a year and 41 inches of snowfall (NOAA 1991–2020 normals, Yale 1 Nnw station).

How hot do summers get in Sandusky, MI?

The average high peaks at 80 °F in July, with about 6 days a year at 90 °F or more.

What kind of soil does 48471 have?

The USDA soil survey maps Parkhill at the center of ZIP 48471: clay loam, poorly drained, pH about 7.3 (neutral).

Did spring come early in Sandusky, MI in 2026?

Spring leaf-out near 48471 came on Apr 12 in 2026, 3 days earlier than the 1991–2020 average (Apr 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sandusky, MI?

Long-day onions: the longest day near 48471 is 15 h 25 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).