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

Planting zone for 48723 — Caro, MI

ZIP code 48723 (Caro, Tuscola 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 9.

Where ZIP 48723 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 9
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 Caro, 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 Caro, 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 24only 10% chance of frost after
First fall frostOctober 9median — 10% chance by Sep 25
Growing season154 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 27 and returns around October 23.

From the NOAA station Caro Wwtp, MI — within 1 mile, elevation 689 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 48723

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 14 – Aug 28
GarlicPlant cloves · Sep 25 – Oct 30
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 7) and first fall frost (Oct 9) 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 48723 came on Apr 11 — 3 days earlier than the 1991–2020 average (Apr 14).

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 Caro, MI.

Soil in Caro, MI

The soil mapped at the center of ZIP 48723 is Thetford — loamy fine sand, somewhat poorly drained.

TextureLoamy fine sanddrains and warms fast; dries out and needs more feeding
pH6.3slightly acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter2.25%moderate
Hydrologic groupA/Ddrains fast once dried out; wet otherwise
Farmland classFarmland of local importanceUSDA classification

Map unit: Thetford loamy fine sand, 0 to 4 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 48723; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Caro, MI

Summer high82 °Faverage high, July
Winter low15 °Faverage low, January
Hot days10days a year at 90 °F or more
Freezing nights152nights a year at 32 °F or less
Growing degree days2,488base 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)
Precipitation34.3 inper year, rain and melted snow
Snowfall42 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 29 °F, low 15 °F 29°15° JanFebruary: average high 32 °F, low 15 °F 32°15° FebMarch: average high 42 °F, low 23 °F 42°23° MarApril: average high 55 °F, low 34 °F 55°34° AprMay: average high 68 °F, low 45 °F 68°45° MayJune: average high 78 °F, low 55 °F 78°55° JunJuly: average high 82 °F, low 60 °F 82°60° JulAugust: average high 80 °F, low 57 °F 80°57° AugSeptember: average high 73 °F, low 50 °F 73°50° SepOctober: average high 60 °F, low 40 °F 60°40° OctNovember: average high 46 °F, low 31 °F 46°31° NovDecember: average high 35 °F, low 22 °F 35°22° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 2.18 in precipitation, 13.1 in snowfall 2.2❄13 JanFebruary: 1.63 in precipitation, 8 in snowfall 1.6❄8 FebMarch: 1.92 in precipitation, 5.5 in snowfall 1.9❄6 MarApril: 3.59 in precipitation, 1 in snowfall 3.6❄1 AprMay: 3.69 in precipitation 3.7 MayJune: 3.58 in precipitation 3.6 JunJuly: 3.48 in precipitation 3.5 JulAugust: 3.32 in precipitation 3.3 AugSeptember: 3.21 in precipitation 3.2 SepOctober: 3.11 in precipitation 3.1 OctNovember: 2.47 in precipitation, 2.3 in snowfall 2.5❄2 NovDecember: 2.12 in precipitation, 11.7 in snowfall 2.1❄12 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Caro Wwtp, MI (within 1 mile); precipitation: Caro Wwtp, MI (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

487446a
Mayville, MI · 10 mi
487296a
Deford, MI · 11 mi
487336a
Fairgrove, MI · 11 mi
487016a
Akron, MI · 11 mi
487416a
Kingston, MI · 12 mi
487676a
Unionville, MI · 12 mi
487686a
Vassar, MI · 13 mi
487606a
Silverwood, MI · 13 mi

Michigan planting zones →

Questions about 48723

What planting zone is ZIP code 48723?

ZIP code 48723 (Caro, 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 Caro, MI?

The median last spring frost (32 °F) near 48723 is May 7; after May 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Caro Wwtp station.

When is the first frost in Caro, MI?

The median first fall frost near 48723 is October 9, giving a median frost-free growing season of 154 days.

When should I plant tomatoes in 48723?

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 48723 get?

About 34.3 inches of precipitation a year and 42 inches of snowfall (NOAA 1991–2020 normals, Caro Wwtp station).

How hot do summers get in Caro, MI?

The average high peaks at 82 °F in July, with about 10 days a year at 90 °F or more.

What kind of soil does 48723 have?

The USDA soil survey maps Thetford at the center of ZIP 48723: loamy fine sand, somewhat poorly drained, pH about 6.3 (slightly acidic).

Did spring come early in Caro, MI in 2026?

Spring leaf-out near 48723 came on Apr 11 in 2026, 3 days earlier than the 1991–2020 average (Apr 14), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Caro, MI?

Long-day onions: the longest day near 48723 is 15 h 25 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 48723 change?

Yes. The 2012 USDA map put 48723 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.