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

Planting zone for 49870 — Norway, MI

ZIP code 49870 (Norway, Dickinson County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 17 and the first fall frost October 1.

Where ZIP 49870 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.

Zone4b−25 to −20 °F

Coldest night−31.7 to −28.9 °C

Last frostMay 17

First frostOct 1

2012 zone4a

Was 4a 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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Norway, 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 Norway, 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 plantsMay 31only 10% chance of frost after

First fall frostOctober 1median — 10% chance by Sep 17

Growing season135 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 4 and returns around October 11.

From the NOAA station Iron Mtn-Kingsford Wwtp, MI — 11 miles away, elevation 1,070 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 49870

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 6 – Aug 20

GarlicPlant cloves · Sep 17 – Oct 22

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 17) and first fall frost (Oct 1) 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 49870 came on Apr 22 — 3 days earlier than the 1991–2020 average (Apr 25).

average
Apr 252026
Apr 22

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 4b in Michigan

514 plants native to the lower 48 states, recorded in Michigan, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. 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 Norway, MI.

Soil in Norway, MI

The soil mapped at the center of ZIP 49870 is Waucedah — mucky sandy loam, very poorly drained.

TextureMucky sandy loamdrains and warms fast; dries out and needs more feeding

pH6.7neutral; most vegetables like 6.0–7.0

DrainageVery poorly drainedconsider raised beds

Organic matter16%high

Hydrologic groupB/Dmoderate when drained; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Waucedah-Cathro complex.

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 49870; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Norway, MI

Summer high80 °Faverage high, July

Winter low4 °Faverage low, January

Hot days6days a year at 90 °F or more

Freezing nights182nights a year at 32 °F or less

Growing degree days2,062base 50 °F — the season’s usable heat

Longest day15 h 44 mindaylight on June 21

Shortest day8 h 39 mindaylight on December 21

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

Precipitation31.5 inper year, rain and melted snow

Snowfall61 inper year; 118 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: Iron Mtn-Kingsford Wwtp, MI (11 mi away); precipitation: Iron Mtn-Kingsford Wwtp, MI (11 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.

Iron Mountain, MI · 8 mi

498024b

Kingsford, MI · 11 mi

498344b

Foster City, MI · 11 mi

Michigan planting zones →

Questions about 49870

What planting zone is ZIP code 49870?

ZIP code 49870 (Norway, MI) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Norway, MI?

The median last spring frost (32 °F) near 49870 is May 17; after May 31 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Iron Mtn-Kingsford Wwtp station.

When is the first frost in Norway, MI?

The median first fall frost near 49870 is October 1, giving a median frost-free growing season of 135 days.

When should I plant tomatoes in 49870?

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 49870 get?

About 31.5 inches of precipitation a year and 61 inches of snowfall (NOAA 1991–2020 normals, Iron Mtn-Kingsford Wwtp station).

How hot do summers get in Norway, MI?

The average high peaks at 80 °F in July, with about 6 days a year at 90 °F or more.

What kind of soil does 49870 have?

The USDA soil survey maps Waucedah at the center of ZIP 49870: mucky sandy loam, very poorly drained, pH about 6.7 (neutral).

Did spring come early in Norway, MI in 2026?

Spring leaf-out near 49870 came on Apr 22 in 2026, 3 days earlier than the 1991–2020 average (Apr 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Norway, MI?

Long-day onions: the longest day near 49870 is 15 h 44 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 49870 change?

Yes. The 2012 USDA map put 49870 in zone 4a; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.