Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 49808 — Big Bay, MI

ZIP code 49808 (Big Bay, Marquette County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 22 and the first fall frost October 6.

Where ZIP 49808 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.

Zone5b−15 to −10 °F

Coldest night−26.1 to −23.3 °C

Last frostMay 22

First frostOct 6

2012 zone5b

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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Big Bay, 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 Big Bay, 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 frostOctober 6median — 10% chance by Sep 20

Growing season137 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 9 and returns around October 21.

From the NOAA station Big Bay 1nw, MI — 5 miles away, elevation 764 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 49808

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 11 – Aug 25

GarlicPlant cloves · Sep 22 – Oct 27

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 22) and first fall frost (Oct 6) 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 49808 came on May 3 — about the same time as the 1991–2020 average (May 1).

average
May 12026
May 3

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 5b in Michigan

564 plants native to the lower 48 states, recorded in Michigan, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.

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 Big Bay, MI.

Soil in Big Bay, MI

The soil mapped at the center of ZIP 49808 is Frohling — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer

pH4.5strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter75%high

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Frohling-Tokiahok complex, 8 to 35 percent slopes, dissected, very stony.

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 49808; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Big Bay, MI

Summer high75 °Faverage high, July

Winter low10 °Faverage low, January

Hot days5days a year at 90 °F or more

Freezing nights181nights a year at 32 °F or less

Growing degree days1,729base 50 °F — the season’s usable heat

Longest day15 h 52 mindaylight on June 21

Shortest day8 h 32 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation32.8 inper year, rain and melted snow

Snowfall132 inper year; 145 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Big Bay 1nw, MI (5 mi away); precipitation: Big Bay 1nw, MI (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

National Mine, MI · 19 mi

498614a

Michigamme, MI · 23 mi

499465a

Lanse, MI · 24 mi

498555b

Marquette, MI · 26 mi

498494b

Ishpeming, MI · 28 mi

498664b

Negaunee, MI · 31 mi

Michigan planting zones →

Questions about 49808

What planting zone is ZIP code 49808?

ZIP code 49808 (Big Bay, MI) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Big Bay, MI?

The median last spring frost (32 °F) near 49808 is May 22; after June 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Big Bay 1nw station.

When is the first frost in Big Bay, MI?

The median first fall frost near 49808 is October 6, giving a median frost-free growing season of 137 days.

When should I plant tomatoes in 49808?

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 49808 get?

About 32.8 inches of precipitation a year and 132 inches of snowfall (NOAA 1991–2020 normals, Big Bay 1nw station).

How hot do summers get in Big Bay, MI?

The average high peaks at 75 °F in July, with about 5 days a year at 90 °F or more.

What kind of soil does 49808 have?

The USDA soil survey maps Frohling at the center of ZIP 49808: moderately decomposed plant material, well drained, pH about 4.5 (strongly acidic).

Did spring come early in Big Bay, MI in 2026?

Spring leaf-out near 49808 came on May 3 in 2026, about the same as the 1991–2020 average (May 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Big Bay, MI?

Long-day onions: the longest day near 49808 is 15 h 52 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).