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

Planting zone for Warren, MI

Warren, MI is in USDA zone 6b across its 7 ZIP codes. The median last spring frost is April 21 and the first fall frost October 31.

Warren on the zone map

Outlined: its 5 ZIP code areas · 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
ZIP codes7
Last frostApr 21
First frostOct 31
Growing season190 days

6b 7 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 Warren, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 21median — 50% chance of a later frost
Safe for tender plantsMay 6only 10% chance of frost after
First fall frostOctober 31median — 10% chance by Oct 17
Growing season190 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 8 and returns around November 9.

From the NOAA station Detroit City Airport, MI, elevation 627 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 Warren

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 10 – Mar 24
SpinachSow outdoors · Mar 10 – Mar 31
Broccoli, cabbageStart indoors · Feb 10 – Feb 24
Broccoli, cabbageTransplant · Mar 31 – Apr 14
Onion setsPlant outdoors · Mar 24 – Apr 7
PotatoesPlant outdoors · Mar 31 – Apr 14
LettuceSow outdoors · Mar 24 – Apr 7
Carrots, beetsSow outdoors · Mar 31 – Apr 14
TomatoesStart indoors · Feb 24 – Mar 10
TomatoesTransplant · Apr 28 – May 12
Peppers, eggplantStart indoors · Feb 10 – Feb 24
Peppers, eggplantTransplant · May 5 – May 19
BeansSow outdoors · Apr 28 – May 12
Sweet cornSow outdoors · Apr 28 – May 12
Cucumbers, squashSow outdoors · Apr 28 – May 12
Fall lettuce, spinachSow outdoors · Sep 5 – Sep 19
GarlicPlant cloves · Oct 17 – Nov 21
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 21) and first fall frost (Oct 31) 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 48397 came on Apr 2 — 5 days earlier than the 1991–2020 average (Apr 7).

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.

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 221

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 175

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 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °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 Warren, MI.

Soil in Warren, MI

The soil mapped at the center of ZIP 48397 is Lenawee — silty clay loam, poorly drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH6.5neutral; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter4.8%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classPrime farmland if drainedUSDA classification

Map unit: Lenawee silty clay loam, 0 to 1 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 48397; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Warren, MI

Summer high84 °Faverage high, July
Winter low20 °Faverage low, January
Hot days13days a year at 90 °F or more
Freezing nights113nights a year at 32 °F or less
Growing degree days3,094base 50 °F — the season’s usable heat
Longest day15 h 18 mindaylight on June 21
Shortest day9 h 03 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation29.9 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 32 °F, low 20 °F 32°20° JanFebruary: average high 35 °F, low 21 °F 35°21° FebMarch: average high 45 °F, low 28 °F 45°28° MarApril: average high 58 °F, low 39 °F 58°39° AprMay: average high 70 °F, low 50 °F 70°50° MayJune: average high 79 °F, low 60 °F 79°60° JunJuly: average high 84 °F, low 65 °F 84°65° JulAugust: average high 81 °F, low 64 °F 81°64° AugSeptember: average high 74 °F, low 56 °F 74°56° SepOctober: average high 61 °F, low 45 °F 61°45° OctNovember: average high 48 °F, low 34 °F 48°34° NovDecember: average high 37 °F, low 26 °F 37°26° Dec

Precipitation by month inches

0″1″2″3″4″January: 1.45 in precipitation 1.4 JanFebruary: 1.41 in precipitation 1.4 FebMarch: 2.02 in precipitation 2.0 MarApril: 2.82 in precipitation 2.8 AprMay: 3.49 in precipitation 3.5 MayJune: 3.10 in precipitation 3.1 JunJuly: 3.22 in precipitation 3.2 JulAugust: 3.10 in precipitation 3.1 AugSeptember: 3.09 in precipitation 3.1 SepOctober: 2.30 in precipitation 2.3 OctNovember: 2.16 in precipitation 2.2 NovDecember: 1.73 in precipitation 1.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Detroit City Airport, MI (6 mi away); precipitation: Detroit City Airport, MI (6 mi away). Daylight is calculated from latitude.

ZIP codes in Warren

480886b
−5 to 0 °F
480896b
−5 to 0 °F
480906b
−5 to 0 °F
480916b
−5 to 0 °F
480926b
−5 to 0 °F
480936b
−5 to 0 °F
483976b
−5 to 0 °F

Michigan planting zones →

Questions about Warren

What planting zone is Warren, MI?

Warren, MI is in USDA hardiness zone 6b on the 2023 map (6b: −5 to 0 °F).

When is the last frost in Warren, MI?

The median last spring frost is April 21 and the median first fall frost is October 31 (NOAA 1991–2020 normals, Detroit City Airport station).

When can I plant a garden in Warren, MI?

Cool-season crops like peas and spinach go in around Mar 10 – Mar 31; tomatoes, peppers, beans and squash after about Apr 28, once frost risk has passed.

What kind of onions grow in Warren, MI?

Long-day onions: the longest day is 15 h 18 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Warren, MI get?

About 29.9 inches of precipitation a year (NOAA 1991–2020 normals).