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

Planting zone for 48710 — University Center, MI

ZIP code 48710 (University Center, Bay County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 26 and the first fall frost October 17.

Where ZIP 48710 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 frostApr 26
First frostOct 17
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 University Center, 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 University Center, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 26median — 50% chance of a later frost
Safe for tender plantsMay 13only 10% chance of frost after
First fall frostOctober 17median — 10% chance by Oct 2
Growing season172 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 15 and returns around October 31.

From the NOAA station Saginaw Mbs Intl Airport, MI — 5 miles away, elevation 659 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 48710

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 15 – Mar 29
SpinachSow outdoors · Mar 15 – Apr 5
Broccoli, cabbageStart indoors · Feb 15 – Mar 1
Broccoli, cabbageTransplant · Apr 5 – Apr 19
Onion setsPlant outdoors · Mar 29 – Apr 12
PotatoesPlant outdoors · Apr 5 – Apr 19
LettuceSow outdoors · Mar 29 – Apr 12
Carrots, beetsSow outdoors · Apr 5 – Apr 19
TomatoesStart indoors · Mar 1 – Mar 15
TomatoesTransplant · May 3 – May 17
Peppers, eggplantStart indoors · Feb 15 – Mar 1
Peppers, eggplantTransplant · May 10 – May 24
BeansSow outdoors · May 3 – May 17
Sweet cornSow outdoors · May 3 – May 17
Cucumbers, squashSow outdoors · May 3 – May 17
Fall lettuce, spinachSow outdoors · Aug 22 – Sep 5
GarlicPlant cloves · Oct 3 – Nov 7
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 26) and first fall frost (Oct 17) 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 48710 came on Apr 11 — about the same time as the 1991–2020 average (Apr 13).

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 University Center, MI.

Soil in University Center, MI

The soil mapped at the center of ZIP 48710 is Tappan — loam, poorly drained.

TextureLoama good balance for most vegetables
pH7.5slightly alkaline; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter5.08%high
Hydrologic groupB/Dmoderate when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Tappan 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 48710; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in University Center, MI

Summer high82 °Faverage high, July
Winter low16 °Faverage low, January
Hot days9days a year at 90 °F or more
Freezing nights139nights a year at 32 °F or less
Growing degree days2,693base 50 °F — the season’s usable heat
Longest day15 h 26 mindaylight on June 21
Shortest day8 h 56 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation32.1 inper year, rain and melted snow
Snowfall49 inper year; 65 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 30 °F, low 16 °F 30°16° JanFebruary: average high 32 °F, low 17 °F 32°17° FebMarch: average high 42 °F, low 26 °F 42°26° MarApril: average high 56 °F, low 36 °F 56°36° AprMay: average high 69 °F, low 48 °F 69°48° MayJune: average high 79 °F, low 58 °F 79°58° JunJuly: average high 82 °F, low 61 °F 82°61° JulAugust: average high 80 °F, low 59 °F 80°59° AugSeptember: average high 73 °F, low 52 °F 73°52° SepOctober: average high 60 °F, low 41 °F 60°41° OctNovember: average high 46 °F, low 32 °F 46°32° NovDecember: average high 35 °F, low 23 °F 35°23° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 1.92 in precipitation, 13.9 in snowfall 1.9❄14 JanFebruary: 1.77 in precipitation, 11.4 in snowfall 1.8❄11 FebMarch: 2.02 in precipitation, 6 in snowfall 2.0❄6 MarApril: 3.19 in precipitation, 2.4 in snowfall 3.2❄2 AprMay: 3.41 in precipitation 3.4 MayJune: 3.28 in precipitation 3.3 JunJuly: 2.83 in precipitation 2.8 JulAugust: 3.85 in precipitation 3.9 AugSeptember: 2.81 in precipitation 2.8 SepOctober: 2.91 in precipitation, 0.2 in snowfall 2.9 OctNovember: 2.28 in precipitation, 3.3 in snowfall 2.3❄3 NovDecember: 1.85 in precipitation, 11.8 in snowfall 1.9❄12 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Saginaw Mbs Intl Airport, MI (5 mi away); precipitation: Saginaw Mbs Intl Airport, MI (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

487066a
Bay City, MI · 4 mi
486046a
Saginaw, MI · 4 mi
487086a
Bay City, MI · 7 mi
486036a
Saginaw, MI · 7 mi
486056a
Saginaw, MI · 7 mi
487246a
Carrollton, MI · 7 mi
486116a
Auburn, MI · 8 mi
486236a
Freeland, MI · 8 mi

Michigan planting zones →

Questions about 48710

What planting zone is ZIP code 48710?

ZIP code 48710 (University Center, 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 University Center, MI?

The median last spring frost (32 °F) near 48710 is April 26; after May 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Saginaw Mbs Intl Airport station.

When is the first frost in University Center, MI?

The median first fall frost near 48710 is October 17, giving a median frost-free growing season of 172 days.

When should I plant tomatoes in 48710?

Start tomato seeds indoors around Mar 1 – Mar 15 and set transplants outside around May 3 – May 17, one to three weeks after the median last frost.

How much rain and snow does 48710 get?

About 32.1 inches of precipitation a year and 49 inches of snowfall (NOAA 1991–2020 normals, Saginaw Mbs Intl Airport station).

How hot do summers get in University Center, MI?

The average high peaks at 82 °F in July, with about 9 days a year at 90 °F or more.

What kind of soil does 48710 have?

The USDA soil survey maps Tappan at the center of ZIP 48710: loam, poorly drained, pH about 7.5 (slightly alkaline).

Did spring come early in University Center, MI in 2026?

Spring leaf-out near 48710 came on Apr 11 in 2026, about the same as the 1991–2020 average (Apr 13), according to the USA National Phenology Network Spring Index.

What kind of onions grow in University Center, MI?

Long-day onions: the longest day near 48710 is 15 h 26 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).