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

Planting zone for 55338 — Green Isle, MN

ZIP code 55338 (Green Isle, Sibley County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is April 24 and the first fall frost October 15.

Where ZIP 55338 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 frostApr 24
First frostOct 15
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 Green Isle, MN…

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 Green Isle, MN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 24median — 50% chance of a later frost
Safe for tender plantsMay 8only 10% chance of frost after
First fall frostOctober 15median — 10% chance by Sep 30
Growing season170 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 14 and returns around October 24.

From the NOAA station Gaylord, MN — 14 miles away, elevation 1,020 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 55338

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 13 – Mar 27
SpinachSow outdoors · Mar 13 – Apr 3
Broccoli, cabbageStart indoors · Feb 13 – Feb 27
Broccoli, cabbageTransplant · Apr 3 – Apr 17
Onion setsPlant outdoors · Mar 27 – Apr 10
PotatoesPlant outdoors · Apr 3 – Apr 17
LettuceSow outdoors · Mar 27 – Apr 10
Carrots, beetsSow outdoors · Apr 3 – Apr 17
TomatoesStart indoors · Feb 27 – Mar 13
TomatoesTransplant · May 1 – May 15
Peppers, eggplantStart indoors · Feb 13 – Feb 27
Peppers, eggplantTransplant · May 8 – May 22
BeansSow outdoors · May 1 – May 15
Sweet cornSow outdoors · May 1 – May 15
Cucumbers, squashSow outdoors · May 1 – May 15
Fall lettuce, spinachSow outdoors · Aug 20 – Sep 3
GarlicPlant cloves · Oct 1 – Nov 5
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 24) and first fall frost (Oct 15) 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 55338 came on Apr 9 — 8 days earlier than the 1991–2020 average (Apr 17).

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 Minnesota

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

Trees 47

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °Fbalsam fir60 ft · blooms mid summer · low shade tolerance · to −43 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °F

Shrubs 88

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 190

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °F

Grasses 156

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °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 °Fbasin wildrye5 ft · blooms early spring · high shade tolerance · to −43 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 4

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °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 Green Isle, MN.

Soil in Green Isle, MN

The soil mapped at the center of ZIP 55338 is Okoboji — mucky silty clay loam, very poorly drained.

TextureMucky silty clay loamholds water and nutrients; slow to drain and warm up
pH7.0neutral; most vegetables like 6.0–7.0
DrainageVery poorly drainedconsider raised beds
Organic matter14%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Okoboji mucky silty clay loam.

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 55338; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Green Isle, MN

Summer high82 °Faverage high, July
Winter low6 °Faverage low, January
Hot days12days a year at 90 °F or more
Freezing nights161nights a year at 32 °F or less
Growing degree days2,710base 50 °F — the season’s usable heat
Longest day15 h 34 mindaylight on June 21
Shortest day8 h 48 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

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 21 °F, low 6 °F 21°6° JanFebruary: average high 26 °F, low 9 °F 26°9° FebMarch: average high 38 °F, low 22 °F 38°22° MarApril: average high 54 °F, low 35 °F 54°35° AprMay: average high 68 °F, low 48 °F 68°48° MayJune: average high 78 °F, low 59 °F 78°59° JunJuly: average high 82 °F, low 63 °F 82°63° JulAugust: average high 80 °F, low 60 °F 80°60° AugSeptember: average high 72 °F, low 51 °F 72°51° SepOctober: average high 57 °F, low 38 °F 57°38° OctNovember: average high 41 °F, low 25 °F 41°25° NovDecember: average high 27 °F, low 13 °F 27°13° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 0.73 in precipitation 0.7 JanFebruary: 0.81 in precipitation 0.8 FebMarch: 1.57 in precipitation 1.6 MarApril: 2.84 in precipitation 2.8 AprMay: 4.42 in precipitation 4.4 MayJune: 5.10 in precipitation 5.1 JunJuly: 3.74 in precipitation 3.7 JulAugust: 4.44 in precipitation 4.4 AugSeptember: 3.29 in precipitation 3.3 SepOctober: 2.56 in precipitation 2.6 OctNovember: 1.57 in precipitation 1.6 NovDecember: 1.04 in precipitation 1.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Gaylord, MN (14 mi away); precipitation: Glencoe 0.3 Wsw, MN (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4b.

553394b
Hamburg, MN · 4 mi
553684b
Norwood Young America, MN · 7 mi
553074b
Arlington, MN · 8 mi
553704b
Plato, MN · 8 mi
560444b
Henderson, MN · 8 mi
553974b
Young America, MN · 11 mi
553364b
Glencoe, MN · 11 mi
553664b
New Auburn, MN · 11 mi

Minnesota planting zones →

Questions about 55338

What planting zone is ZIP code 55338?

ZIP code 55338 (Green Isle, MN) 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 Green Isle, MN?

The median last spring frost (32 °F) near 55338 is April 24; after May 8 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Gaylord station.

When is the first frost in Green Isle, MN?

The median first fall frost near 55338 is October 15, giving a median frost-free growing season of 170 days.

When should I plant tomatoes in 55338?

Start tomato seeds indoors around Feb 27 – Mar 13 and set transplants outside around May 1 – May 15, one to three weeks after the median last frost.

How much rain and snow does 55338 get?

About 32.1 inches of precipitation a year (NOAA 1991–2020 normals, Glencoe 0.3 Wsw station).

How hot do summers get in Green Isle, MN?

The average high peaks at 82 °F in July, with about 12 days a year at 90 °F or more.

What kind of soil does 55338 have?

The USDA soil survey maps Okoboji at the center of ZIP 55338: mucky silty clay loam, very poorly drained, pH about 7.0 (neutral).

Did spring come early in Green Isle, MN in 2026?

Spring leaf-out near 55338 came on Apr 9 in 2026, 8 days earlier than the 1991–2020 average (Apr 17), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Green Isle, MN?

Long-day onions: the longest day near 55338 is 15 h 34 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).