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

Planting zone for 49879 — Republic, MI

ZIP code 49879 (Republic, Marquette County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is June 5 and the first fall frost September 10.

Where ZIP 49879 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.

Zone4a−30 to −25 °F

Coldest night−34.4 to −31.7 °C

Last frostJun 5

First frostSep 10

2012 zone4a

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 4a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Republic, 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 Republic, MI

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostJune 5median — 50% chance of a later frost

Safe for tender plantsJune 24only 10% chance of frost after

First fall frostSeptember 10median — 10% chance by Aug 23

Growing season96 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 23 and returns around September 28.

From the NOAA station Clarksburg, MI — 15 miles away, elevation 1,555 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 49879

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 24 – May 8

SpinachSow outdoors · Apr 24 – May 15

Broccoli, cabbageStart indoors · Mar 27 – Apr 10

Broccoli, cabbageTransplant · May 15 – May 29

Onion setsPlant outdoors · May 8 – May 22

PotatoesPlant outdoors · May 15 – May 29

LettuceSow outdoors · May 8 – May 22

Carrots, beetsSow outdoors · May 15 – May 29

TomatoesStart indoors · Apr 10 – Apr 24

TomatoesTransplant · Jun 12 – Jun 26

Peppers, eggplantStart indoors · Mar 27 – Apr 10

Peppers, eggplantTransplant · Jun 19 – Jul 3

BeansSow outdoors · Jun 12 – Jun 26

Sweet cornSow outdoors · Jun 12 – Jun 26

Cucumbers, squashSow outdoors · Jun 12 – Jun 26

Fall lettuce, spinachSow outdoors · Jul 16 – Jul 30

GarlicPlant cloves · Aug 27 – Oct 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 5) and first fall frost (Sep 10) 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 49879 came on May 1 — about the same time as the 1991–2020 average (Apr 30).

average
Apr 302026
May 1

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 4a in Michigan

443 plants native to the lower 48 states, recorded in Michigan, and rated by the USDA to survive −30 °F or colder — the bottom of zone 4a. 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 Republic, MI.

Soil in Republic, MI

The soil mapped at the center of ZIP 49879 is Goodman — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer

pH5.1strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter75%high

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Goodman-Sundog-Wabeno silt loams, 6 to 18 percent slopes, bouldery.

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 49879; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Republic, MI

Summer high77 °Faverage high, July

Winter low0 °Faverage low, February

Hot days2days a year at 90 °F or more

Freezing nights218nights a year at 32 °F or less

Growing degree days1,514base 50 °F — the season’s usable heat

Longest day15 h 48 mindaylight on June 21

Shortest day8 h 36 mindaylight on December 21

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

Precipitation30.1 inper year, rain and melted snow

Snowfall118 inper year; 147 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: Champion Van Riper Pk, MI (13 mi away); precipitation: Clarksburg, MI (15 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.

498154b

Channing, MI · 12 mi

498494b

Ishpeming, MI · 15 mi

498144a

Champion, MI · 17 mi

498614a

Michigamme, MI · 17 mi

499204a

Crystal Falls, MI · 18 mi

Covington, MI · 21 mi

Michigan planting zones →

Questions about 49879

What planting zone is ZIP code 49879?

ZIP code 49879 (Republic, MI) is in USDA hardiness zone 4a on the 2023 map: the coldest night of an average winter reaches −30 to −25 °F (−34.4 to −31.7 °C).

When is the last frost in Republic, MI?

The median last spring frost (32 °F) near 49879 is June 5; after June 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Clarksburg station.

When is the first frost in Republic, MI?

The median first fall frost near 49879 is September 10, giving a median frost-free growing season of 96 days.

When should I plant tomatoes in 49879?

Start tomato seeds indoors around Apr 10 – Apr 24 and set transplants outside around Jun 12 – Jun 26, one to three weeks after the median last frost.

How much rain and snow does 49879 get?

About 30.1 inches of precipitation a year and 118 inches of snowfall (NOAA 1991–2020 normals, Clarksburg station).

How hot do summers get in Republic, MI?

The average high peaks at 77 °F in July, with about 2 days a year at 90 °F or more.

What kind of soil does 49879 have?

The USDA soil survey maps Goodman at the center of ZIP 49879: moderately decomposed plant material, well drained, pH about 5.1 (strongly acidic).

Did spring come early in Republic, MI in 2026?

Spring leaf-out near 49879 came on May 1 in 2026, about the same as the 1991–2020 average (Apr 30), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Republic, MI?

Long-day onions: the longest day near 49879 is 15 h 48 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).