Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 49705 — Afton, MI

ZIP code 49705 (Afton, Cheboygan County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is June 7 and the first fall frost September 14.

Where ZIP 49705 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.

Zone4b−25 to −20 °F

Coldest night−31.7 to −28.9 °C

Last frostJun 7

First frostSep 14

2012 zone4b

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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Afton, 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 Afton, MI

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostJune 7median — 50% chance of a later frost

Safe for tender plantsJune 29only 10% chance of frost after

First fall frostSeptember 14median — 10% chance by Aug 24

Growing season95 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 24 and returns around September 29.

From the NOAA station Vanderbilt 11ene, MI — 12 miles away, elevation 906 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 49705

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 26 – May 10

SpinachSow outdoors · Apr 26 – May 17

Broccoli, cabbageStart indoors · Mar 29 – Apr 12

Broccoli, cabbageTransplant · May 17 – May 31

Onion setsPlant outdoors · May 10 – May 24

PotatoesPlant outdoors · May 17 – May 31

LettuceSow outdoors · May 10 – May 24

Carrots, beetsSow outdoors · May 17 – May 31

TomatoesStart indoors · Apr 12 – Apr 26

TomatoesTransplant · Jun 14 – Jun 28

Peppers, eggplantStart indoors · Mar 29 – Apr 12

Peppers, eggplantTransplant · Jun 21 – Jul 5

BeansSow outdoors · Jun 14 – Jun 28

Sweet cornSow outdoors · Jun 14 – Jun 28

Cucumbers, squashSow outdoors · Jun 14 – Jun 28

Fall lettuce, spinachSow outdoors · Jul 20 – Aug 3

GarlicPlant cloves · Aug 31 – Oct 5

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 7) and first fall frost (Sep 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 49705 came on Apr 22 — about the same time as the 1991–2020 average (Apr 23).

average
Apr 232026
Apr 22

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 4b in Michigan

514 plants native to the lower 48 states, recorded in Michigan, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. Each links to its USDA PLANTS profile.

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 Afton, MI.

Soil in Afton, MI

The soil mapped at the center of ZIP 49705 is Onaway — loam, well drained.

TextureLoama good balance for most vegetables

pH6.5neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Onaway 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 49705; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Afton, MI

Summer high80 °Faverage high, July

Winter low6 °Faverage low, February

Hot days8days a year at 90 °F or more

Freezing nights200nights a year at 32 °F or less

Growing degree days1,737base 50 °F — the season’s usable heat

Longest day15 h 40 mindaylight on June 21

Shortest day8 h 43 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation32.4 inper year, rain and melted snow

Snowfall84 inper year; 128 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Vanderbilt 11ene, MI (12 mi away); precipitation: Vanderbilt 11ene, MI (12 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.

497494b

Indian River, MI · 8 mi

Topinabee, MI · 11 mi

497175a

Burt Lake, MI · 12 mi

497955a

Vanderbilt, MI · 14 mi

497615a

Mullett Lake, MI · 15 mi

497215a

Cheboygan, MI · 16 mi

Michigan planting zones →

Questions about 49705

What planting zone is ZIP code 49705?

ZIP code 49705 (Afton, MI) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Afton, MI?

The median last spring frost (32 °F) near 49705 is June 7; after June 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Vanderbilt 11ene station.

When is the first frost in Afton, MI?

The median first fall frost near 49705 is September 14, giving a median frost-free growing season of 95 days.

When should I plant tomatoes in 49705?

Start tomato seeds indoors around Apr 12 – Apr 26 and set transplants outside around Jun 14 – Jun 28, one to three weeks after the median last frost.

How much rain and snow does 49705 get?

About 32.4 inches of precipitation a year and 84 inches of snowfall (NOAA 1991–2020 normals, Vanderbilt 11ene station).

How hot do summers get in Afton, MI?

The average high peaks at 80 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 49705 have?

The USDA soil survey maps Onaway at the center of ZIP 49705: loam, well drained, pH about 6.5 (neutral).

Did spring come early in Afton, MI in 2026?

Spring leaf-out near 49705 came on Apr 22 in 2026, about the same as the 1991–2020 average (Apr 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Afton, MI?

Long-day onions: the longest day near 49705 is 15 h 40 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).