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

Planting zone for 48625 — Harrison, MI

ZIP code 48625 (Harrison, Clare County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 9 and the first fall frost October 4.

Where ZIP 48625 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 9
First frostOct 4
2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Harrison, 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 Harrison, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 9median — 50% chance of a later frost
Safe for tender plantsMay 23only 10% chance of frost after
First fall frostOctober 4median — 10% chance by Sep 22
Growing season148 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 30 and returns around October 17.

From the NOAA station Gladwin, MI — 18 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 48625

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 28 – Apr 11
SpinachSow outdoors · Mar 28 – Apr 18
Broccoli, cabbageStart indoors · Feb 28 – Mar 14
Broccoli, cabbageTransplant · Apr 18 – May 2
Onion setsPlant outdoors · Apr 11 – Apr 25
PotatoesPlant outdoors · Apr 18 – May 2
LettuceSow outdoors · Apr 11 – Apr 25
Carrots, beetsSow outdoors · Apr 18 – May 2
TomatoesStart indoors · Mar 14 – Mar 28
TomatoesTransplant · May 16 – May 30
Peppers, eggplantStart indoors · Feb 28 – Mar 14
Peppers, eggplantTransplant · May 23 – Jun 6
BeansSow outdoors · May 16 – May 30
Sweet cornSow outdoors · May 16 – May 30
Cucumbers, squashSow outdoors · May 16 – May 30
Fall lettuce, spinachSow outdoors · Aug 9 – Aug 23
GarlicPlant cloves · Sep 20 – Oct 25
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Oct 4) 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 48625 came on Apr 16 — 5 days earlier than the 1991–2020 average (Apr 21).

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 Harrison, MI.

Soil in Harrison, MI

The soil mapped at the center of ZIP 48625 is Markey — muck, very poorly drained.

TextureMucktop layer
DrainageVery poorly drainedconsider raised beds
Organic matter82.5%high
Hydrologic groupA/Ddrains fast once dried out; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Markey muck.

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 48625; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Harrison, MI

Summer high82 °Faverage high, July
Winter low13 °Faverage low, January
Hot days8days a year at 90 °F or more
Freezing nights165nights a year at 32 °F or less
Growing degree days2,274base 50 °F — the season’s usable heat
Longest day15 h 30 mindaylight on June 21
Shortest day8 h 53 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation33.9 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 29 °F, low 13 °F 29°13° JanFebruary: average high 32 °F, low 13 °F 32°13° FebMarch: average high 43 °F, low 20 °F 43°20° MarApril: average high 56 °F, low 31 °F 56°31° AprMay: average high 68 °F, low 43 °F 68°43° MayJune: average high 78 °F, low 53 °F 78°53° JunJuly: average high 82 °F, low 57 °F 82°57° JulAugust: average high 80 °F, low 55 °F 80°55° AugSeptember: average high 73 °F, low 47 °F 73°47° SepOctober: average high 60 °F, low 37 °F 60°37° OctNovember: average high 46 °F, low 28 °F 46°28° NovDecember: average high 34 °F, low 20 °F 34°20° Dec

Precipitation by month inches

0″1″2″3″4″January: 2.18 in precipitation 2.2 JanFebruary: 1.75 in precipitation 1.8 FebMarch: 2.01 in precipitation 2.0 MarApril: 3.42 in precipitation 3.4 AprMay: 3.52 in precipitation 3.5 MayJune: 3.58 in precipitation 3.6 JunJuly: 3.08 in precipitation 3.1 JulAugust: 3.48 in precipitation 3.5 AugSeptember: 2.79 in precipitation 2.8 SepOctober: 3.42 in precipitation 3.4 OctNovember: 2.56 in precipitation 2.6 NovDecember: 2.06 in precipitation 2.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Gladwin, MI (18 mi away); precipitation: Harrison 5.2 Ese, MI (8 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.

486335a
Lake George, MI · 9 mi
496325a
Falmouth, MI · 14 mi
496655a
Marion, MI · 15 mi
486175b
Clare, MI · 15 mi
486225b
Farwell, MI · 15 mi
486325a
Lake, MI · 17 mi
486515a
Prudenville, MI · 18 mi
486295a
Houghton Lake, MI · 18 mi

Michigan planting zones →

Questions about 48625

What planting zone is ZIP code 48625?

ZIP code 48625 (Harrison, 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 Harrison, MI?

The median last spring frost (32 °F) near 48625 is May 9; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Gladwin station.

When is the first frost in Harrison, MI?

The median first fall frost near 48625 is October 4, giving a median frost-free growing season of 148 days.

When should I plant tomatoes in 48625?

Start tomato seeds indoors around Mar 14 – Mar 28 and set transplants outside around May 16 – May 30, one to three weeks after the median last frost.

How much rain and snow does 48625 get?

About 33.9 inches of precipitation a year (NOAA 1991–2020 normals, Harrison 5.2 Ese station).

How hot do summers get in Harrison, MI?

The average high peaks at 82 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 48625 have?

The USDA soil survey maps Markey at the center of ZIP 48625: muck, very poorly drained.

Did spring come early in Harrison, MI in 2026?

Spring leaf-out near 48625 came on Apr 16 in 2026, 5 days earlier than the 1991–2020 average (Apr 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Harrison, MI?

Long-day onions: the longest day near 48625 is 15 h 30 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).