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

Planting zone for 49670 — Northport, MI

ZIP code 49670 (Northport, Leelanau County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is May 9 and the first fall frost October 26.

Where ZIP 49670 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.

Zone6b−5 to 0 °F

Coldest night−20.6 to −17.8 °C

Last frostMay 9

First frostOct 26

2012 zone6a

Was 6a 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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Northport, 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 Northport, MI

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 9median — 50% chance of a later frost

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

First fall frostOctober 26median — 10% chance by Oct 11

Growing season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 27 and returns around November 8.

From the NOAA station Northport 2w, MI — 2 miles away, elevation 745 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 49670

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 28 – Apr 11

SpinachSow outdoors · Mar 28 – Apr 18

Broccoli, cabbageStart indoors · Feb 28 – Mar 14

Broccoli, cabbageTransplant · Apr 18 – May 2

Onion setsPlant outdoors · Apr 11 – Apr 25

PotatoesPlant outdoors · Apr 18 – May 2

LettuceSow outdoors · Apr 11 – Apr 25

Carrots, beetsSow outdoors · Apr 18 – May 2

TomatoesStart indoors · Mar 14 – Mar 28

TomatoesTransplant · May 16 – May 30

Peppers, eggplantStart indoors · Feb 28 – Mar 14

Peppers, eggplantTransplant · May 23 – Jun 6

BeansSow outdoors · May 16 – May 30

Sweet cornSow outdoors · May 16 – May 30

Cucumbers, squashSow outdoors · May 16 – May 30

Fall lettuce, spinachSow outdoors · Aug 31 – Sep 14

GarlicPlant cloves · Oct 12 – Nov 16

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Oct 26) 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 49670 came on Apr 22 — about the same time as the 1991–2020 average (Apr 22).

average
Apr 222026
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 6b in Michigan

582 plants native to the lower 48 states, recorded in Michigan, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 Northport, MI.

Soil in Northport, MI

The soil mapped at the center of ZIP 49670 is Leelanau — loamy sand, well drained.

TextureLoamy sanddrains and warms fast; dries out and needs more feeding

pH6.5neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupAwater soaks in fast

Farmland classFarmland of local importanceUSDA classification

Map unit: Leelanau-East Lake loamy sands, 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 49670; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Northport, MI

Summer high75 °Faverage high, July

Winter low17 °Faverage low, February

Hot days1days a year at 90 °F or more

Freezing nights144nights a year at 32 °F or less

Growing degree days2,017base 50 °F — the season’s usable heat

Longest day15 h 38 mindaylight on June 21

Shortest day8 h 45 mindaylight on December 21

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

Precipitation32.9 inper year, rain and melted snow

Snowfall91 inper year; 114 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: Northport 2w, MI (2 mi away); precipitation: Northport 2w, MI (2 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.

496746b

Omena, MI · 5 mi

496826b

Suttons Bay, MI · 9 mi

496536b

Lake Leelanau, MI · 11 mi

496276a

Eastport, MI · 13 mi

496736b

Old Mission, MI · 13 mi

496486a

Kewadin, MI · 16 mi

497295b

Ellsworth, MI · 16 mi

496225b

Central Lake, MI · 17 mi

Michigan planting zones →

Questions about 49670

What planting zone is ZIP code 49670?

ZIP code 49670 (Northport, MI) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Northport, MI?

The median last spring frost (32 °F) near 49670 is May 9; after May 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Northport 2w station.

When is the first frost in Northport, MI?

The median first fall frost near 49670 is October 26, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 49670?

Start tomato seeds indoors around Mar 14 – Mar 28 and set transplants outside around May 16 – May 30, one to three weeks after the median last frost.

How much rain and snow does 49670 get?

About 32.9 inches of precipitation a year and 91 inches of snowfall (NOAA 1991–2020 normals, Northport 2w station).

How hot do summers get in Northport, MI?

The average high peaks at 75 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 49670 have?

The USDA soil survey maps Leelanau at the center of ZIP 49670: loamy sand, well drained, pH about 6.5 (neutral).

Did spring come early in Northport, MI in 2026?

Spring leaf-out near 49670 came on Apr 22 in 2026, about the same as the 1991–2020 average (Apr 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Northport, MI?

Long-day onions: the longest day near 49670 is 15 h 38 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 49670 change?

Yes. The 2012 USDA map put 49670 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.