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

Planting zone for 49961 — Sidnaw, MI

ZIP code 49961 (Sidnaw, Houghton County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 25 and the first fall frost September 25.

Where ZIP 49961 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 frostMay 25

First frostSep 25

2012 zone4a

Was 4a 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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Sidnaw, 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 Sidnaw, MI

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 25median — 50% chance of a later frost

Safe for tender plantsJune 11only 10% chance of frost after

First fall frostSeptember 25median — 10% chance by Sep 10

Growing season123 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 10 and returns around October 7.

From the NOAA station Watton 2wsw, MI — 6 miles away, elevation 1,394 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 49961

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 13 – Apr 27

SpinachSow outdoors · Apr 13 – May 4

Broccoli, cabbageStart indoors · Mar 16 – Mar 30

Broccoli, cabbageTransplant · May 4 – May 18

Onion setsPlant outdoors · Apr 27 – May 11

PotatoesPlant outdoors · May 4 – May 18

LettuceSow outdoors · Apr 27 – May 11

Carrots, beetsSow outdoors · May 4 – May 18

TomatoesStart indoors · Mar 30 – Apr 13

TomatoesTransplant · Jun 1 – Jun 15

Peppers, eggplantStart indoors · Mar 16 – Mar 30

Peppers, eggplantTransplant · Jun 8 – Jun 22

BeansSow outdoors · Jun 1 – Jun 15

Sweet cornSow outdoors · Jun 1 – Jun 15

Cucumbers, squashSow outdoors · Jun 1 – Jun 15

Fall lettuce, spinachSow outdoors · Jul 31 – Aug 14

GarlicPlant cloves · Sep 11 – Oct 16

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 25) and first fall frost (Sep 25) 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 49961 came on Apr 29 — about the same time as the 1991–2020 average (Apr 29).

average
Apr 292026
Apr 29

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 Sidnaw, MI.

Soil in Sidnaw, MI

The soil mapped at the center of ZIP 49961 is Dawson — peat, very poorly drained.

TexturePeattop layer

DrainageVery poorly drainedconsider raised beds

Organic matter75%high

Hydrologic groupA/Ddrains fast once dried out; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Dawson, Greenwood and Loxley soils, 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 49961; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sidnaw, MI

Summer high76 °Faverage high, July

Winter low6 °Faverage low, January

Hot days1days a year at 90 °F or more

Freezing nights189nights a year at 32 °F or less

Growing degree days1,621base 50 °F — the season’s usable heat

Longest day15 h 49 mindaylight on June 21

Shortest day8 h 35 mindaylight on December 21

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

Precipitation31.9 inper year, rain and melted snow

Snowfall121 inper year; 149 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: Watton 2wsw, MI (6 mi away); precipitation: Watton 2wsw, MI (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

6 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

Trout Creek, MI · 13 mi

499194a

Covington, MI · 13 mi

499525a

Nisula, MI · 18 mi

499354a

Iron River, MI · 19 mi

499644a

Stambaugh, MI · 26 mi

499465a

Lanse, MI · 26 mi

Michigan planting zones →

Questions about 49961

What planting zone is ZIP code 49961?

ZIP code 49961 (Sidnaw, 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 Sidnaw, MI?

The median last spring frost (32 °F) near 49961 is May 25; after June 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Watton 2wsw station.

When is the first frost in Sidnaw, MI?

The median first fall frost near 49961 is September 25, giving a median frost-free growing season of 123 days.

When should I plant tomatoes in 49961?

Start tomato seeds indoors around Mar 30 – Apr 13 and set transplants outside around Jun 1 – Jun 15, one to three weeks after the median last frost.

How much rain and snow does 49961 get?

About 31.9 inches of precipitation a year and 121 inches of snowfall (NOAA 1991–2020 normals, Watton 2wsw station).

How hot do summers get in Sidnaw, MI?

The average high peaks at 76 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 49961 have?

The USDA soil survey maps Dawson at the center of ZIP 49961: peat, very poorly drained.

Did spring come early in Sidnaw, MI in 2026?

Spring leaf-out near 49961 came on Apr 29 in 2026, about the same as the 1991–2020 average (Apr 29), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sidnaw, MI?

Long-day onions: the longest day near 49961 is 15 h 49 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 49961 change?

Yes. The 2012 USDA map put 49961 in zone 4a; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.