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

Planting zone for 49637 — Grawn, MI

ZIP code 49637 (Grawn, Grand Traverse County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 9 and the first fall frost October 15.

Where ZIP 49637 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 9

First frostOct 15

2012 zone5a

Was 5a on the 2012 map — a full zone warmer now. 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 Grawn, 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 Grawn, 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 23only 10% chance of frost after

First fall frostOctober 15median — 10% chance by Oct 1

Growing season156 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 28 and returns around October 30.

From the NOAA station Traverse City Munson, MI — 9 miles away, elevation 637 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 49637

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 20 – Sep 3

GarlicPlant cloves · Oct 1 – Nov 5

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Oct 15) 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 49637 came on Apr 16 — about the same time as the 1991–2020 average (Apr 18).

average
Apr 182026
Apr 16

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.

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 Grawn, MI.

Soil in Grawn, MI

The soil mapped at the center of ZIP 49637 is Kalkaska — loamy sand, somewhat excessively drained.

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

pH4.8strongly acidic; most vegetables like 6.0–7.0

DrainageSomewhat excessively drainednatural drainage class

Organic matter2.5%moderate

Hydrologic groupAwater soaks in fast

Farmland classNot prime farmlandUSDA classification

Map unit: Kalkaska loamy sand, 0 to 2 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 49637; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Grawn, MI

Summer high79 °Faverage high, July

Winter low14 °Faverage low, February

Hot days6days a year at 90 °F or more

Freezing nights154nights a year at 32 °F or less

Growing degree days2,173base 50 °F — the season’s usable heat

Longest day15 h 34 mindaylight on June 21

Shortest day8 h 48 mindaylight on December 21

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

Precipitation36.2 inper year, rain and melted snow

Snowfall101 inper year; 103 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: Traverse City Munson, MI (9 mi away); precipitation: Traverse City Munson, MI (9 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.

496856a

Traverse City, MI · 4 mi

496436a

Interlochen, MI · 6 mi

496205b

Buckley, MI · 8 mi

496846a

Traverse City, MI · 9 mi

Traverse City, MI · 11 mi

Michigan planting zones →

Questions about 49637

What planting zone is ZIP code 49637?

ZIP code 49637 (Grawn, 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 Grawn, MI?

The median last spring frost (32 °F) near 49637 is May 9; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Traverse City Munson station.

When is the first frost in Grawn, MI?

The median first fall frost near 49637 is October 15, giving a median frost-free growing season of 156 days.

When should I plant tomatoes in 49637?

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 49637 get?

About 36.2 inches of precipitation a year and 101 inches of snowfall (NOAA 1991–2020 normals, Traverse City Munson station).

How hot do summers get in Grawn, MI?

The average high peaks at 79 °F in July, with about 6 days a year at 90 °F or more.

What kind of soil does 49637 have?

The USDA soil survey maps Kalkaska at the center of ZIP 49637: loamy sand, somewhat excessively drained, pH about 4.8 (strongly acidic).

Did spring come early in Grawn, MI in 2026?

Spring leaf-out near 49637 came on Apr 16 in 2026, about the same as the 1991–2020 average (Apr 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Grawn, MI?

Long-day onions: the longest day near 49637 is 15 h 34 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 49637 change?

Yes. The 2012 USDA map put 49637 in zone 5a; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.