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

Planting zone for 49690 — Williamsburg, MI

ZIP code 49690 (Williamsburg, Grand Traverse County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 12 and the first fall frost October 16.

Where ZIP 49690 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 12
First frostOct 16
2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Williamsburg, 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 Williamsburg, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 12median — 50% chance of a later frost
Safe for tender plantsMay 27only 10% chance of frost after
First fall frostOctober 16median — 10% chance by Oct 1
Growing season155 daysfrost-free, median

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

From the NOAA station Traverse City Cherry Cptl Airport, MI — 10 miles away, elevation 617 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 49690

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 31 – Apr 14
SpinachSow outdoors · Mar 31 – Apr 21
Broccoli, cabbageStart indoors · Mar 3 – Mar 17
Broccoli, cabbageTransplant · Apr 21 – May 5
Onion setsPlant outdoors · Apr 14 – Apr 28
PotatoesPlant outdoors · Apr 21 – May 5
LettuceSow outdoors · Apr 14 – Apr 28
Carrots, beetsSow outdoors · Apr 21 – May 5
TomatoesStart indoors · Mar 17 – Mar 31
TomatoesTransplant · May 19 – Jun 2
Peppers, eggplantStart indoors · Mar 3 – Mar 17
Peppers, eggplantTransplant · May 26 – Jun 9
BeansSow outdoors · May 19 – Jun 2
Sweet cornSow outdoors · May 19 – Jun 2
Cucumbers, squashSow outdoors · May 19 – Jun 2
Fall lettuce, spinachSow outdoors · Aug 21 – Sep 4
GarlicPlant cloves · Oct 2 – Nov 6
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 12) and first fall frost (Oct 16) 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 49690 came on Apr 16 — 4 days earlier than the 1991–2020 average (Apr 20).

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.

Trees 58

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 105

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °F

Wildflowers & perennials 220

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °F

Grasses 174

alpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °F

Vines 8

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °F

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 Williamsburg, MI.

Soil in Williamsburg, MI

The soil mapped at the center of ZIP 49690 is Emmet — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH6.1slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: Emmet sandy loam, 2 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 49690; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Williamsburg, MI

Summer high81 °Faverage high, July
Winter low16 °Faverage low, February
Hot days9days a year at 90 °F or more
Freezing nights149nights a year at 32 °F or less
Growing degree days2,441base 50 °F — the season’s usable heat
Longest day15 h 35 mindaylight on June 21
Shortest day8 h 47 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation35.9 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 29 °F, low 17 °F 29°17° JanFebruary: average high 31 °F, low 16 °F 31°16° FebMarch: average high 41 °F, low 23 °F 41°23° MarApril: average high 54 °F, low 33 °F 54°33° AprMay: average high 67 °F, low 43 °F 67°43° MayJune: average high 77 °F, low 54 °F 77°54° JunJuly: average high 81 °F, low 59 °F 81°59° JulAugust: average high 80 °F, low 59 °F 80°59° AugSeptember: average high 72 °F, low 52 °F 72°52° SepOctober: average high 59 °F, low 41 °F 59°41° OctNovember: average high 46 °F, low 32 °F 46°32° NovDecember: average high 35 °F, low 24 °F 35°24° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.45 in precipitation 2.5 JanFebruary: 1.84 in precipitation 1.8 FebMarch: 2.04 in precipitation 2.0 MarApril: 3.28 in precipitation 3.3 AprMay: 3.34 in precipitation 3.3 MayJune: 3.19 in precipitation 3.2 JunJuly: 2.83 in precipitation 2.8 JulAugust: 3.40 in precipitation 3.4 AugSeptember: 3.99 in precipitation 4.0 SepOctober: 4.05 in precipitation 4.0 OctNovember: 2.95 in precipitation 3.0 NovDecember: 2.50 in precipitation 2.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Traverse City Cherry Cptl Airport, MI (10 mi away); precipitation: Traverse City 4.7ese, MI (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

496106a
Acme, MI · 5 mi
496766a
Rapid City, MI · 6 mi
496866b
Traverse City, MI · 9 mi
496965b
Traverse City, MI · 9 mi
496296a
Elk Rapids, MI · 9 mi
496125b
Alden, MI · 10 mi
496805b
South Boardman, MI · 12 mi
496736b
Old Mission, MI · 13 mi

Michigan planting zones →

Questions about 49690

What planting zone is ZIP code 49690?

ZIP code 49690 (Williamsburg, 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 Williamsburg, MI?

The median last spring frost (32 °F) near 49690 is May 12; after May 27 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Traverse City Cherry Cptl Airport station.

When is the first frost in Williamsburg, MI?

The median first fall frost near 49690 is October 16, giving a median frost-free growing season of 155 days.

When should I plant tomatoes in 49690?

Start tomato seeds indoors around Mar 17 – Mar 31 and set transplants outside around May 19 – Jun 2, one to three weeks after the median last frost.

How much rain and snow does 49690 get?

About 35.9 inches of precipitation a year (NOAA 1991–2020 normals, Traverse City 4.7ese station).

How hot do summers get in Williamsburg, MI?

The average high peaks at 81 °F in July, with about 9 days a year at 90 °F or more.

What kind of soil does 49690 have?

The USDA soil survey maps Emmet at the center of ZIP 49690: sandy loam, well drained, pH about 6.1 (slightly acidic).

Did spring come early in Williamsburg, MI in 2026?

Spring leaf-out near 49690 came on Apr 16 in 2026, 4 days earlier than the 1991–2020 average (Apr 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Williamsburg, MI?

Long-day onions: the longest day near 49690 is 15 h 35 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 49690 change?

Yes. The 2012 USDA map put 49690 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.