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

Planting zone for 49246 — Horton, MI

ZIP code 49246 (Horton, Jackson County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 1 and the first fall frost October 14.

Where ZIP 49246 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 1
First frostOct 14
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 Horton, 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 Horton, MI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 1median — 50% chance of a later frost
Safe for tender plantsMay 18only 10% chance of frost after
First fall frostOctober 14median — 10% chance by Sep 30
Growing season164 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 20 and returns around October 28.

From the NOAA station Jackson Reynolds Field, MI — 10 miles away, elevation 997 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 49246

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 20 – Apr 3
SpinachSow outdoors · Mar 20 – Apr 10
Broccoli, cabbageStart indoors · Feb 20 – Mar 6
Broccoli, cabbageTransplant · Apr 10 – Apr 24
Onion setsPlant outdoors · Apr 3 – Apr 17
PotatoesPlant outdoors · Apr 10 – Apr 24
LettuceSow outdoors · Apr 3 – Apr 17
Carrots, beetsSow outdoors · Apr 10 – Apr 24
TomatoesStart indoors · Mar 6 – Mar 20
TomatoesTransplant · May 8 – May 22
Peppers, eggplantStart indoors · Feb 20 – Mar 6
Peppers, eggplantTransplant · May 15 – May 29
BeansSow outdoors · May 8 – May 22
Sweet cornSow outdoors · May 8 – May 22
Cucumbers, squashSow outdoors · May 8 – May 22
Fall lettuce, spinachSow outdoors · Aug 19 – Sep 2
GarlicPlant cloves · Sep 30 – Nov 4
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 1) and first fall frost (Oct 14) 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 49246 came on Mar 26 — 15 days earlier than the 1991–2020 average (Apr 10).

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 Horton, MI.

Soil in Horton, MI

The soil mapped at the center of ZIP 49246 is Riddles — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.9%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: Riddles sandy loam, 1 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 49246; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Horton, MI

Summer high83 °Faverage high, July
Winter low18 °Faverage low, January
Hot days8days a year at 90 °F or more
Freezing nights137nights a year at 32 °F or less
Growing degree days2,767base 50 °F — the season’s usable heat
Longest day15 h 15 mindaylight on June 21
Shortest day9 h 06 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation37.7 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 31 °F, low 18 °F 31°18° JanFebruary: average high 35 °F, low 19 °F 35°19° FebMarch: average high 45 °F, low 27 °F 45°27° MarApril: average high 59 °F, low 37 °F 59°37° AprMay: average high 70 °F, low 48 °F 70°48° MayJune: average high 79 °F, low 57 °F 79°57° JunJuly: average high 83 °F, low 61 °F 83°61° JulAugust: average high 80 °F, low 59 °F 80°59° AugSeptember: average high 74 °F, low 52 °F 74°52° SepOctober: average high 61 °F, low 41 °F 61°41° OctNovember: average high 48 °F, low 32 °F 48°32° NovDecember: average high 36 °F, low 24 °F 36°24° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.42 in precipitation 2.4 JanFebruary: 2.16 in precipitation 2.2 FebMarch: 2.19 in precipitation 2.2 MarApril: 3.53 in precipitation 3.5 AprMay: 4.27 in precipitation 4.3 MayJune: 3.98 in precipitation 4.0 JunJuly: 3.69 in precipitation 3.7 JulAugust: 3.64 in precipitation 3.6 AugSeptember: 3.45 in precipitation 3.5 SepOctober: 3.30 in precipitation 3.3 OctNovember: 2.74 in precipitation 2.7 NovDecember: 2.37 in precipitation 2.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Jackson Reynolds Field, MI (10 mi away); precipitation: Jonesville 5.9 Ene, MI (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

492576a
Moscow, MI · 5 mi
492416a
Hanover, MI · 5 mi
492836a
Spring Arbor, MI · 6 mi
492346a
Clarklake, MI · 7 mi
492496a
Jerome, MI · 7 mi
492826a
Somerset Center, MI · 8 mi
492336a
Cement City, MI · 8 mi
492376a
Concord, MI · 8 mi

Michigan planting zones →

Questions about 49246

What planting zone is ZIP code 49246?

ZIP code 49246 (Horton, 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 Horton, MI?

The median last spring frost (32 °F) near 49246 is May 1; after May 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Jackson Reynolds Field station.

When is the first frost in Horton, MI?

The median first fall frost near 49246 is October 14, giving a median frost-free growing season of 164 days.

When should I plant tomatoes in 49246?

Start tomato seeds indoors around Mar 6 – Mar 20 and set transplants outside around May 8 – May 22, one to three weeks after the median last frost.

How much rain and snow does 49246 get?

About 37.7 inches of precipitation a year (NOAA 1991–2020 normals, Jonesville 5.9 Ene station).

How hot do summers get in Horton, MI?

The average high peaks at 83 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 49246 have?

The USDA soil survey maps Riddles at the center of ZIP 49246: sandy loam, well drained, pH about 6.2 (slightly acidic).

Did spring come early in Horton, MI in 2026?

Spring leaf-out near 49246 came on Mar 26 in 2026, 15 days earlier than the 1991–2020 average (Apr 10), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Horton, MI?

Long-day onions: the longest day near 49246 is 15 h 15 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 49246 change?

Yes. The 2012 USDA map put 49246 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.