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

Planting zone for Port Huron, MI

Port Huron, MI is in USDA zone 6b across its 2 ZIP codes. The median last spring frost is April 19 and the first fall frost November 3.

Port Huron on the zone map

Outlined: its 1 ZIP code areas · 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
ZIP codes2
Last frostApr 19
First frostNov 3
Growing season196 days

6b 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Port Huron, 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 Port Huron, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 19median — 50% chance of a later frost
Safe for tender plantsMay 4only 10% chance of frost after
First fall frostNovember 3median — 10% chance by Oct 20
Growing season196 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 7 and returns around November 12.

From the NOAA station Port Huron, MI, elevation 591 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 Port Huron

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 8 – Mar 22
SpinachSow outdoors · Mar 8 – Mar 29
Broccoli, cabbageStart indoors · Feb 8 – Feb 22
Broccoli, cabbageTransplant · Mar 29 – Apr 12
Onion setsPlant outdoors · Mar 22 – Apr 5
PotatoesPlant outdoors · Mar 29 – Apr 12
LettuceSow outdoors · Mar 22 – Apr 5
Carrots, beetsSow outdoors · Mar 29 – Apr 12
TomatoesStart indoors · Feb 22 – Mar 8
TomatoesTransplant · Apr 26 – May 10
Peppers, eggplantStart indoors · Feb 8 – Feb 22
Peppers, eggplantTransplant · May 3 – May 17
BeansSow outdoors · Apr 26 – May 10
Sweet cornSow outdoors · Apr 26 – May 10
Cucumbers, squashSow outdoors · Apr 26 – May 10
Fall lettuce, spinachSow outdoors · Sep 8 – Sep 22
GarlicPlant cloves · Oct 20 – Nov 24
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Nov 3) 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 48060 came on Apr 8 — 5 days earlier than the 1991–2020 average (Apr 13).

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 Michigan

582 plants native to the lower 48 states, recorded in Michigan, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 221

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 175

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 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °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 Port Huron, MI.

Soil in Port Huron, MI

The soil mapped at the center of ZIP 48060 is Allendale — loamy fine sand, somewhat poorly drained.

TextureLoamy fine sanddrains and warms fast; dries out and needs more feeding
pH5.8moderately acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter2.25%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of local importanceUSDA classification

Map unit: Allendale-Hoytville complex, 0 to 6 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 48060; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Port Huron, MI

Summer high81 °Faverage high, July
Winter low20 °Faverage low, January
Hot days10days a year at 90 °F or more
Freezing nights122nights a year at 32 °F or less
Growing degree days2,898base 50 °F — the season’s usable heat
Longest day15 h 22 mindaylight on June 21
Shortest day9 h 00 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation34.5 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 31 °F, low 20 °F 31°20° JanFebruary: average high 33 °F, low 21 °F 33°21° FebMarch: average high 42 °F, low 28 °F 42°28° MarApril: average high 54 °F, low 38 °F 54°38° AprMay: average high 67 °F, low 49 °F 67°49° MayJune: average high 76 °F, low 59 °F 76°59° JunJuly: average high 81 °F, low 65 °F 81°65° JulAugust: average high 80 °F, low 64 °F 80°64° AugSeptember: average high 73 °F, low 57 °F 73°57° SepOctober: average high 61 °F, low 46 °F 61°46° OctNovember: average high 47 °F, low 35 °F 47°35° NovDecember: average high 36 °F, low 26 °F 36°26° Dec

Precipitation by month inches

0″1″2″3″4″January: 2.42 in precipitation 2.4 JanFebruary: 1.92 in precipitation 1.9 FebMarch: 2.08 in precipitation 2.1 MarApril: 3.24 in precipitation 3.2 AprMay: 3.55 in precipitation 3.5 MayJune: 3.51 in precipitation 3.5 JunJuly: 3.41 in precipitation 3.4 JulAugust: 3.35 in precipitation 3.4 AugSeptember: 3.13 in precipitation 3.1 SepOctober: 2.90 in precipitation 2.9 OctNovember: 2.71 in precipitation 2.7 NovDecember: 2.24 in precipitation 2.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Port Huron, MI (2 mi away); precipitation: Port Huron 1.6 W, MI (within 1 mile). Daylight is calculated from latitude.

ZIP codes in Port Huron

480606b
−5 to 0 °F
480616b
−5 to 0 °F

Michigan planting zones →

Questions about Port Huron

What planting zone is Port Huron, MI?

Port Huron, MI is in USDA hardiness zone 6b on the 2023 map (6b: −5 to 0 °F).

When is the last frost in Port Huron, MI?

The median last spring frost is April 19 and the median first fall frost is November 3 (NOAA 1991–2020 normals, Port Huron station).

When can I plant a garden in Port Huron, MI?

Cool-season crops like peas and spinach go in around Mar 8 – Mar 29; tomatoes, peppers, beans and squash after about Apr 26, once frost risk has passed.

What kind of onions grow in Port Huron, MI?

Long-day onions: the longest day is 15 h 22 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Port Huron, MI get?

About 34.5 inches of precipitation a year (NOAA 1991–2020 normals).