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

Planting zone for 49458 — Walhalla, MI

ZIP code 49458 (Walhalla, Mason County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 17 and the first fall frost October 7.

Where ZIP 49458 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 17
First frostOct 7
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 Walhalla, 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 Walhalla, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 17median — 50% chance of a later frost
Safe for tender plantsJune 1only 10% chance of frost after
First fall frostOctober 7median — 10% chance by Sep 20
Growing season144 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 1 and returns around October 21.

From the NOAA station Ludington 4 Se, MI — 14 miles away, 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 49458

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 5 – Apr 19
SpinachSow outdoors · Apr 5 – Apr 26
Broccoli, cabbageStart indoors · Mar 8 – Mar 22
Broccoli, cabbageTransplant · Apr 26 – May 10
Onion setsPlant outdoors · Apr 19 – May 3
PotatoesPlant outdoors · Apr 26 – May 10
LettuceSow outdoors · Apr 19 – May 3
Carrots, beetsSow outdoors · Apr 26 – May 10
TomatoesStart indoors · Mar 22 – Apr 5
TomatoesTransplant · May 24 – Jun 7
Peppers, eggplantStart indoors · Mar 8 – Mar 22
Peppers, eggplantTransplant · May 31 – Jun 14
BeansSow outdoors · May 24 – Jun 7
Sweet cornSow outdoors · May 24 – Jun 7
Cucumbers, squashSow outdoors · May 24 – Jun 7
Fall lettuce, spinachSow outdoors · Aug 12 – Aug 26
GarlicPlant cloves · Sep 23 – Oct 28
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 17) and first fall frost (Oct 7) 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 49458 came on Apr 11 — 5 days earlier than the 1991–2020 average (Apr 16).

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 Walhalla, MI.

Soil in Walhalla, MI

The soil mapped at the center of ZIP 49458 is Grattan — sand, excessively drained.

TextureSanddrains and warms fast; dries out and needs more feeding
pH4.8strongly acidic; most vegetables like 6.0–7.0
DrainageExcessively drainednatural drainage class
Organic matter4.9%moderate
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Grattan 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 49458; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Walhalla, MI

Summer high79 °Faverage high, July
Winter low17 °Faverage low, January
Hot days5days a year at 90 °F or more
Freezing nights149nights a year at 32 °F or less
Growing degree days2,166base 50 °F — the season’s usable heat
Longest day15 h 29 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)
Precipitation37.3 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 29 °F, low 17 °F 29°17° JanFebruary: average high 32 °F, low 18 °F 32°18° FebMarch: average high 41 °F, low 24 °F 41°24° MarApril: average high 54 °F, low 33 °F 54°33° AprMay: average high 67 °F, low 43 °F 67°43° MayJune: average high 76 °F, low 52 °F 76°52° JunJuly: average high 79 °F, low 58 °F 79°58° JulAugust: average high 78 °F, low 56 °F 78°56° AugSeptember: average high 71 °F, low 50 °F 71°50° SepOctober: average high 57 °F, low 40 °F 57°40° OctNovember: average high 45 °F, low 30 °F 45°30° NovDecember: average high 34 °F, low 22 °F 34°22° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.56 in precipitation 2.6 JanFebruary: 2.02 in precipitation 2.0 FebMarch: 2.28 in precipitation 2.3 MarApril: 3.53 in precipitation 3.5 AprMay: 3.57 in precipitation 3.6 MayJune: 3.38 in precipitation 3.4 JunJuly: 3.45 in precipitation 3.5 JulAugust: 3.43 in precipitation 3.4 AugSeptember: 3.32 in precipitation 3.3 SepOctober: 4.04 in precipitation 4.0 OctNovember: 3.18 in precipitation 3.2 NovDecember: 2.55 in precipitation 2.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Ludington 4 Se, MI (14 mi away); precipitation: Scottville 2se, MI (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

494056a
Custer, MI · 5 mi
494025b
Branch, MI · 5 mi
494106a
Fountain, MI · 6 mi
494546a
Scottville, MI · 8 mi
493045b
Baldwin, MI · 12 mi
494116a
Free Soil, MI · 13 mi
494595b
Walkerville, MI · 15 mi
494316b
Ludington, MI · 15 mi

Michigan planting zones →

Questions about 49458

What planting zone is ZIP code 49458?

ZIP code 49458 (Walhalla, 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 Walhalla, MI?

The median last spring frost (32 °F) near 49458 is May 17; after June 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Ludington 4 Se station.

When is the first frost in Walhalla, MI?

The median first fall frost near 49458 is October 7, giving a median frost-free growing season of 144 days.

When should I plant tomatoes in 49458?

Start tomato seeds indoors around Mar 22 – Apr 5 and set transplants outside around May 24 – Jun 7, one to three weeks after the median last frost.

How much rain and snow does 49458 get?

About 37.3 inches of precipitation a year (NOAA 1991–2020 normals, Scottville 2se station).

How hot do summers get in Walhalla, MI?

The average high peaks at 79 °F in July, with about 5 days a year at 90 °F or more.

What kind of soil does 49458 have?

The USDA soil survey maps Grattan at the center of ZIP 49458: sand, excessively drained, pH about 4.8 (strongly acidic).

Did spring come early in Walhalla, MI in 2026?

Spring leaf-out near 49458 came on Apr 11 in 2026, 5 days earlier than the 1991–2020 average (Apr 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Walhalla, MI?

Long-day onions: the longest day near 49458 is 15 h 29 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 49458 change?

Yes. The 2012 USDA map put 49458 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.