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

Planting zone for 49746 — Hillman, MI

ZIP code 49746 (Hillman, Montmorency County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 22 and the first fall frost September 27.

Where ZIP 49746 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 frostMay 22
First frostSep 27
2012 zone4b

Was 4b 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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Hillman, 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 Hillman, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 22median — 50% chance of a later frost
Safe for tender plantsJune 5only 10% chance of frost after
First fall frostSeptember 27median — 10% chance by Sep 12
Growing season127 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 8 and returns around October 11.

From the NOAA station Atlanta, MI — 10 miles away, elevation 879 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 49746

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 10 – Apr 24
SpinachSow outdoors · Apr 10 – May 1
Broccoli, cabbageStart indoors · Mar 13 – Mar 27
Broccoli, cabbageTransplant · May 1 – May 15
Onion setsPlant outdoors · Apr 24 – May 8
PotatoesPlant outdoors · May 1 – May 15
LettuceSow outdoors · Apr 24 – May 8
Carrots, beetsSow outdoors · May 1 – May 15
TomatoesStart indoors · Mar 27 – Apr 10
TomatoesTransplant · May 29 – Jun 12
Peppers, eggplantStart indoors · Mar 13 – Mar 27
Peppers, eggplantTransplant · Jun 5 – Jun 19
BeansSow outdoors · May 29 – Jun 12
Sweet cornSow outdoors · May 29 – Jun 12
Cucumbers, squashSow outdoors · May 29 – Jun 12
Fall lettuce, spinachSow outdoors · Aug 2 – Aug 16
GarlicPlant cloves · Sep 13 – Oct 18
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 22) and first fall frost (Sep 27) 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 49746 came on Apr 18 — 5 days earlier than the 1991–2020 average (Apr 23).

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 Michigan

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

Trees 54

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 103

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 207

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 166

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 7

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 honeysuckle16 ft · blooms late summer · low shade tolerance · to −33 °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 Hillman, MI.

Soil in Hillman, MI

The soil mapped at the center of ZIP 49746 is Grayling — moderately decomposed plant material, excessively drained.

TextureModerately decomposed plant materialtop layer
DrainageExcessively drainednatural drainage class
Organic matter85%high
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Grayling sand, 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 49746; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hillman, MI

Summer high80 °Faverage high, July
Winter low9 °Faverage low, February
Hot days9days a year at 90 °F or more
Freezing nights193nights a year at 32 °F or less
Growing degree days1,970base 50 °F — the season’s usable heat
Longest day15 h 38 mindaylight on June 21
Shortest day8 h 45 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation32 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 26 °F, low 10 °F 26°10° JanFebruary: average high 29 °F, low 9 °F 29°9° FebMarch: average high 40 °F, low 16 °F 40°16° MarApril: average high 53 °F, low 29 °F 53°29° AprMay: average high 67 °F, low 40 °F 67°40° MayJune: average high 76 °F, low 50 °F 76°50° JunJuly: average high 80 °F, low 55 °F 80°55° JulAugust: average high 79 °F, low 53 °F 79°53° AugSeptember: average high 71 °F, low 45 °F 71°45° SepOctober: average high 57 °F, low 36 °F 57°36° OctNovember: average high 43 °F, low 28 °F 43°28° NovDecember: average high 32 °F, low 19 °F 32°19° Dec

Precipitation by month inches

0″1″2″3″4″January: 1.88 in precipitation 1.9 JanFebruary: 1.53 in precipitation 1.5 FebMarch: 1.83 in precipitation 1.8 MarApril: 3.04 in precipitation 3.0 AprMay: 3.01 in precipitation 3.0 MayJune: 3.22 in precipitation 3.2 JunJuly: 3.33 in precipitation 3.3 JulAugust: 3.23 in precipitation 3.2 AugSeptember: 3.28 in precipitation 3.3 SepOctober: 3.45 in precipitation 3.5 OctNovember: 2.24 in precipitation 2.2 NovDecember: 1.92 in precipitation 1.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Atlanta, MI (10 mi away); precipitation: Atlanta, MI (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

497535a
Lachine, MI · 9 mi
497095a
Atlanta, MI · 11 mi
497435a
Hawks, MI · 14 mi
497445a
Herron, MI · 15 mi
486195a
Comins, MI · 17 mi
497765b
Posen, MI · 18 mi
497475a
Hubbard Lake, MI · 22 mi
497796a
Rogers City, MI · 23 mi

Michigan planting zones →

Questions about 49746

What planting zone is ZIP code 49746?

ZIP code 49746 (Hillman, MI) 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 Hillman, MI?

The median last spring frost (32 °F) near 49746 is May 22; after June 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Atlanta station.

When is the first frost in Hillman, MI?

The median first fall frost near 49746 is September 27, giving a median frost-free growing season of 127 days.

When should I plant tomatoes in 49746?

Start tomato seeds indoors around Mar 27 – Apr 10 and set transplants outside around May 29 – Jun 12, one to three weeks after the median last frost.

How much rain and snow does 49746 get?

About 32 inches of precipitation a year (NOAA 1991–2020 normals, Atlanta station).

How hot do summers get in Hillman, MI?

The average high peaks at 80 °F in July, with about 9 days a year at 90 °F or more.

What kind of soil does 49746 have?

The USDA soil survey maps Grayling at the center of ZIP 49746: moderately decomposed plant material, excessively drained.

Did spring come early in Hillman, MI in 2026?

Spring leaf-out near 49746 came on Apr 18 in 2026, 5 days earlier than the 1991–2020 average (Apr 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Hillman, MI?

Long-day onions: the longest day near 49746 is 15 h 38 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 49746 change?

Yes. The 2012 USDA map put 49746 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.