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

Planting zone for 48426 — Decker, MI

ZIP code 48426 (Decker, Sanilac County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 7 and the first fall frost October 10.

Where ZIP 48426 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 7
First frostOct 10
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 Decker, 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 Decker, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 7median — 50% chance of a later frost
Safe for tender plantsMay 22only 10% chance of frost after
First fall frostOctober 10median — 10% chance by Sep 26
Growing season152 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 28 and returns around October 24.

From the NOAA station Cass City 1 Ssw, MI — 8 miles away, elevation 699 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 48426

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 26 – Apr 9
SpinachSow outdoors · Mar 26 – Apr 16
Broccoli, cabbageStart indoors · Feb 26 – Mar 12
Broccoli, cabbageTransplant · Apr 16 – Apr 30
Onion setsPlant outdoors · Apr 9 – Apr 23
PotatoesPlant outdoors · Apr 16 – Apr 30
LettuceSow outdoors · Apr 9 – Apr 23
Carrots, beetsSow outdoors · Apr 16 – Apr 30
TomatoesStart indoors · Mar 12 – Mar 26
TomatoesTransplant · May 14 – May 28
Peppers, eggplantStart indoors · Feb 26 – Mar 12
Peppers, eggplantTransplant · May 21 – Jun 4
BeansSow outdoors · May 14 – May 28
Sweet cornSow outdoors · May 14 – May 28
Cucumbers, squashSow outdoors · May 14 – May 28
Fall lettuce, spinachSow outdoors · Aug 15 – Aug 29
GarlicPlant cloves · Sep 26 – Oct 31
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 7) and first fall frost (Oct 10) 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 48426 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

Shrubs 105

Wildflowers & perennials 220

Grasses 174

Vines 8

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 Decker, MI.

Soil in Decker, MI

The soil mapped at the center of ZIP 48426 is Parkhill — loam, poorly drained.

TextureLoama good balance for most vegetables
pH7.5slightly alkaline; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter4.4%moderate
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Parkhill loam, 0 to 1 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 48426; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Decker, MI

Summer high80 °Faverage high, July
Winter low13 °Faverage low, January
Hot days7days a year at 90 °F or more
Freezing nights158nights a year at 32 °F or less
Growing degree days2,263base 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)
Precipitation33 inper year, rain and melted snow
Snowfall43 inper year

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 29 °F, low 13 °F 29°13° JanFebruary: average high 32 °F, low 13 °F 32°13° FebMarch: average high 42 °F, low 22 °F 42°22° MarApril: average high 55 °F, low 32 °F 55°32° AprMay: average high 68 °F, low 43 °F 68°43° MayJune: average high 77 °F, low 54 °F 77°54° JunJuly: average high 80 °F, low 57 °F 80°57° JulAugust: average high 79 °F, low 56 °F 79°56° AugSeptember: average high 72 °F, low 49 °F 72°49° SepOctober: average high 59 °F, low 39 °F 59°39° OctNovember: average high 45 °F, low 29 °F 45°29° NovDecember: average high 34 °F, low 21 °F 34°21° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 2.02 in precipitation, 14.4 in snowfall 2.0❄14 JanFebruary: 1.79 in precipitation, 9.3 in snowfall 1.8❄9 FebMarch: 1.99 in precipitation, 5 in snowfall 2.0❄5 MarApril: 3.50 in precipitation, 1.6 in snowfall 3.5❄2 AprMay: 3.52 in precipitation 3.5 MayJune: 3.27 in precipitation 3.3 JunJuly: 3.24 in precipitation 3.2 JulAugust: 3.12 in precipitation 3.1 AugSeptember: 3.17 in precipitation 3.2 SepOctober: 2.91 in precipitation, 0.1 in snowfall 2.9 OctNovember: 2.52 in precipitation, 3.1 in snowfall 2.5❄3 NovDecember: 2.00 in precipitation, 9 in snowfall 2.0❄9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cass City 1 Ssw, MI (8 mi away); precipitation: Cass City 1 Ssw, MI (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

Michigan planting zones →

Questions about 48426

What planting zone is ZIP code 48426?

ZIP code 48426 (Decker, 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 Decker, MI?

The median last spring frost (32 °F) near 48426 is May 7; after May 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cass City 1 Ssw station.

When is the first frost in Decker, MI?

The median first fall frost near 48426 is October 10, giving a median frost-free growing season of 152 days.

When should I plant tomatoes in 48426?

Start tomato seeds indoors around Mar 12 – Mar 26 and set transplants outside around May 14 – May 28, one to three weeks after the median last frost.

How much rain and snow does 48426 get?

About 33 inches of precipitation a year and 43 inches of snowfall (NOAA 1991–2020 normals, Cass City 1 Ssw station).

How hot do summers get in Decker, MI?

The average high peaks at 80 °F in July, with about 7 days a year at 90 °F or more.

What kind of soil does 48426 have?

The USDA soil survey maps Parkhill at the center of ZIP 48426: loam, poorly drained, pH about 7.5 (slightly alkaline).

Did spring come early in Decker, MI in 2026?

Spring leaf-out near 48426 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 Decker, MI?

Long-day onions: the longest day near 48426 is 15 h 25 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 48426 change?

Yes. The 2012 USDA map put 48426 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.