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

Planting zone for 49452 — Rothbury, MI

ZIP code 49452 (Rothbury, Oceana County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 19 and the first fall frost October 4.

Where ZIP 49452 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 19
First frostOct 4
2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Rothbury, 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 Rothbury, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 19median — 50% chance of a later frost
Safe for tender plantsJune 6only 10% chance of frost after
First fall frostOctober 4median — 10% chance by Sep 16
Growing season136 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 5 and returns around October 18.

From the NOAA station Montague 4 Nw, MI — 9 miles away, elevation 650 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 49452

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 7 – Apr 21
SpinachSow outdoors · Apr 7 – Apr 28
Broccoli, cabbageStart indoors · Mar 10 – Mar 24
Broccoli, cabbageTransplant · Apr 28 – May 12
Onion setsPlant outdoors · Apr 21 – May 5
PotatoesPlant outdoors · Apr 28 – May 12
LettuceSow outdoors · Apr 21 – May 5
Carrots, beetsSow outdoors · Apr 28 – May 12
TomatoesStart indoors · Mar 24 – Apr 7
TomatoesTransplant · May 26 – Jun 9
Peppers, eggplantStart indoors · Mar 10 – Mar 24
Peppers, eggplantTransplant · Jun 2 – Jun 16
BeansSow outdoors · May 26 – Jun 9
Sweet cornSow outdoors · May 26 – Jun 9
Cucumbers, squashSow outdoors · May 26 – Jun 9
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 19) 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 49452 came on Apr 10 — 5 days earlier than the 1991–2020 average (Apr 15).

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 Rothbury, MI.

Soil in Rothbury, MI

The soil mapped at the center of ZIP 49452 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 49452; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Rothbury, MI

Summer high79 °Faverage high, July
Winter low19 °Faverage low, January
Hot days2days a year at 90 °F or more
Freezing nights145nights a year at 32 °F or less
Growing degree days2,270base 50 °F — the season’s usable heat
Longest day15 h 26 mindaylight on June 21
Shortest day8 h 56 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation35.2 inper year, rain and melted snow
Snowfall69 inper year; 74 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 30 °F, low 19 °F 30°19° JanFebruary: average high 32 °F, low 19 °F 32°19° FebMarch: average high 42 °F, low 25 °F 42°25° MarApril: average high 55 °F, low 34 °F 55°34° AprMay: average high 67 °F, low 44 °F 67°44° MayJune: average high 75 °F, low 53 °F 75°53° JunJuly: average high 79 °F, low 58 °F 79°58° JulAugust: average high 78 °F, low 57 °F 78°57° AugSeptember: average high 72 °F, low 51 °F 72°51° SepOctober: average high 59 °F, low 41 °F 59°41° OctNovember: average high 45 °F, low 32 °F 45°32° NovDecember: average high 35 °F, low 25 °F 35°25° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 2.60 in precipitation, 26 in snowfall 2.6❄26 JanFebruary: 1.37 in precipitation, 13.8 in snowfall 1.4❄14 FebMarch: 2.28 in precipitation, 6.7 in snowfall 2.3❄7 MarApril: 3.84 in precipitation, 1.7 in snowfall 3.8❄2 AprMay: 3.35 in precipitation 3.4 MayJune: 3.32 in precipitation 3.3 JunJuly: 2.98 in precipitation 3.0 JulAugust: 3.29 in precipitation 3.3 AugSeptember: 3.18 in precipitation 3.2 SepOctober: 4.06 in precipitation, 0.1 in snowfall 4.1 OctNovember: 3.15 in precipitation, 4.7 in snowfall 3.1❄5 NovDecember: 1.77 in precipitation, 15.9 in snowfall 1.8❄16 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Montague 4 Nw, MI (9 mi away); precipitation: Montague 4 Nw, MI (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

494466a
New Era, MI · 6 mi
494376a
Montague, MI · 7 mi
494256a
Holton, MI · 8 mi
494556a
Shelby, MI · 9 mi
494616b
Whitehall, MI · 10 mi
494215b
Hesperia, MI · 11 mi
494576a
Twin Lake, MI · 13 mi
494636b
Sylvan Beach, MI · 13 mi

Michigan planting zones →

Questions about 49452

What planting zone is ZIP code 49452?

ZIP code 49452 (Rothbury, 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 Rothbury, MI?

The median last spring frost (32 °F) near 49452 is May 19; after June 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Montague 4 Nw station.

When is the first frost in Rothbury, MI?

The median first fall frost near 49452 is October 4, giving a median frost-free growing season of 136 days.

When should I plant tomatoes in 49452?

Start tomato seeds indoors around Mar 24 – Apr 7 and set transplants outside around May 26 – Jun 9, one to three weeks after the median last frost.

How much rain and snow does 49452 get?

About 35.2 inches of precipitation a year and 69 inches of snowfall (NOAA 1991–2020 normals, Montague 4 Nw station).

How hot do summers get in Rothbury, MI?

The average high peaks at 79 °F in July, with about 2 days a year at 90 °F or more.

What kind of soil does 49452 have?

The USDA soil survey maps Grattan at the center of ZIP 49452: sand, excessively drained, pH about 4.8 (strongly acidic).

Did spring come early in Rothbury, MI in 2026?

Spring leaf-out near 49452 came on Apr 10 in 2026, 5 days earlier than the 1991–2020 average (Apr 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Rothbury, MI?

Long-day onions: the longest day near 49452 is 15 h 26 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).