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

Planting zone for 48105 — Ann Arbor, MI

ZIP code 48105 (Ann Arbor, Washtenaw County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 3 and the first fall frost October 13.

Where ZIP 48105 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 3
First frostOct 13
2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Ann Arbor, 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 Ann Arbor, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 3median — 50% chance of a later frost
Safe for tender plantsMay 20only 10% chance of frost after
First fall frostOctober 13median — 10% chance by Sep 29
Growing season160 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 23 and returns around October 26.

From the NOAA station Ann Arbor U Of Mich, MI — 2 miles away, elevation 814 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 48105

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 22 – Apr 5
SpinachSow outdoors · Mar 22 – Apr 12
Broccoli, cabbageStart indoors · Feb 22 – Mar 8
Broccoli, cabbageTransplant · Apr 12 – Apr 26
Onion setsPlant outdoors · Apr 5 – Apr 19
PotatoesPlant outdoors · Apr 12 – Apr 26
LettuceSow outdoors · Apr 5 – Apr 19
Carrots, beetsSow outdoors · Apr 12 – Apr 26
TomatoesStart indoors · Mar 8 – Mar 22
TomatoesTransplant · May 10 – May 24
Peppers, eggplantStart indoors · Feb 22 – Mar 8
Peppers, eggplantTransplant · May 17 – May 31
BeansSow outdoors · May 10 – May 24
Sweet cornSow outdoors · May 10 – May 24
Cucumbers, squashSow outdoors · May 10 – May 24
Fall lettuce, spinachSow outdoors · Aug 18 – Sep 1
GarlicPlant cloves · Sep 29 – Nov 3
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 3) and first fall frost (Oct 13) 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 48105 came on Apr 2 — 7 days earlier than the 1991–2020 average (Apr 9).

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 Ann Arbor, MI.

Soil in Ann Arbor, MI

The soil mapped at the center of ZIP 48105 is Oshtemo — loamy sand, well drained.

TextureLoamy sanddrains and warms fast; dries out and needs more feeding
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.75%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classprime farmlandUSDA classification

Map unit: Oshtemo loamy sand, 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 48105; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Ann Arbor, MI

Summer high84 °Faverage high, July
Winter low16 °Faverage low, January
Hot days12days a year at 90 °F or more
Freezing nights130nights a year at 32 °F or less
Growing degree days2,801base 50 °F — the season’s usable heat
Longest day15 h 17 mindaylight on June 21
Shortest day9 h 05 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation38.3 inper year, rain and melted snow
Snowfall61 inper year; 59 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 32 °F, low 16 °F 32°16° JanFebruary: average high 35 °F, low 18 °F 35°18° FebMarch: average high 46 °F, low 25 °F 46°25° MarApril: average high 60 °F, low 36 °F 60°36° AprMay: average high 71 °F, low 47 °F 71°47° MayJune: average high 80 °F, low 56 °F 80°56° JunJuly: average high 84 °F, low 60 °F 84°60° JulAugust: average high 82 °F, low 59 °F 82°59° AugSeptember: average high 75 °F, low 52 °F 75°52° SepOctober: average high 62 °F, low 41 °F 62°41° OctNovember: average high 48 °F, low 31 °F 48°31° NovDecember: average high 36 °F, low 22 °F 36°22° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 2.96 in precipitation, 18.3 in snowfall 3.0❄18 JanFebruary: 2.51 in precipitation, 15.3 in snowfall 2.5❄15 FebMarch: 2.82 in precipitation, 8.3 in snowfall 2.8❄8 MarApril: 3.44 in precipitation, 2.6 in snowfall 3.4❄3 AprMay: 3.84 in precipitation 3.8 MayJune: 3.91 in precipitation 3.9 JunJuly: 3.52 in precipitation 3.5 JulAugust: 3.52 in precipitation 3.5 AugSeptember: 3.18 in precipitation 3.2 SepOctober: 2.99 in precipitation, 0.1 in snowfall 3.0 OctNovember: 2.82 in precipitation, 4.1 in snowfall 2.8❄4 NovDecember: 2.75 in precipitation, 12.7 in snowfall 2.8❄13 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Ann Arbor U Of Mich, MI (2 mi away); precipitation: Ann Arbor U Of Mich, MI (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

481096a
Ann Arbor, MI · 3 mi
481046a
Ann Arbor, MI · 5 mi
481986a
Ypsilanti, MI · 7 mi
481896a
Whitmore Lake, MI · 7 mi
481086a
Ann Arbor, MI · 8 mi
481756a
Salem, MI · 8 mi
481786a
South Lyon, MI · 8 mi
481706a
Plymouth, MI · 9 mi

All 8 ZIP codes in Ann Arbor → · Michigan planting zones →

Questions about 48105

What planting zone is ZIP code 48105?

ZIP code 48105 (Ann Arbor, 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 Ann Arbor, MI?

The median last spring frost (32 °F) near 48105 is May 3; after May 20 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Ann Arbor U Of Mich station.

When is the first frost in Ann Arbor, MI?

The median first fall frost near 48105 is October 13, giving a median frost-free growing season of 160 days.

When should I plant tomatoes in 48105?

Start tomato seeds indoors around Mar 8 – Mar 22 and set transplants outside around May 10 – May 24, one to three weeks after the median last frost.

How much rain and snow does 48105 get?

About 38.3 inches of precipitation a year and 61 inches of snowfall (NOAA 1991–2020 normals, Ann Arbor U Of Mich station).

How hot do summers get in Ann Arbor, MI?

The average high peaks at 84 °F in July, with about 12 days a year at 90 °F or more.

What kind of soil does 48105 have?

The USDA soil survey maps Oshtemo at the center of ZIP 48105: loamy sand, well drained, pH about 6.2 (slightly acidic).

Did spring come early in Ann Arbor, MI in 2026?

Spring leaf-out near 48105 came on Apr 2 in 2026, 7 days earlier than the 1991–2020 average (Apr 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Ann Arbor, MI?

Long-day onions: the longest day near 48105 is 15 h 17 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).