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

Planting zone for 51556 — Modale, IA

ZIP code 51556 (Modale, Harrison County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 22 and the first fall frost October 17.

Where ZIP 51556 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.

Zone5b−15 to −10 °F
Coldest night−26.1 to −23.3 °C
Last frostApr 22
First frostOct 17
2012 zone5b

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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Modale, IA…

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 Modale, IA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 22median — 50% chance of a later frost
Safe for tender plantsMay 5only 10% chance of frost after
First fall frostOctober 17median — 10% chance by Sep 30
Growing season177 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 12 and returns around October 27.

From the NOAA station Blair, NE — 8 miles away, elevation 1,089 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 51556

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 11 – Mar 25
SpinachSow outdoors · Mar 11 – Apr 1
Broccoli, cabbageStart indoors · Feb 11 – Feb 25
Broccoli, cabbageTransplant · Apr 1 – Apr 15
Onion setsPlant outdoors · Mar 25 – Apr 8
PotatoesPlant outdoors · Apr 1 – Apr 15
LettuceSow outdoors · Mar 25 – Apr 8
Carrots, beetsSow outdoors · Apr 1 – Apr 15
TomatoesStart indoors · Feb 25 – Mar 11
TomatoesTransplant · Apr 29 – May 13
Peppers, eggplantStart indoors · Feb 11 – Feb 25
Peppers, eggplantTransplant · May 6 – May 20
BeansSow outdoors · Apr 29 – May 13
Sweet cornSow outdoors · Apr 29 – May 13
Cucumbers, squashSow outdoors · Apr 29 – May 13
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 22) 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 51556 came on Mar 11 — 22 days earlier than the 1991–2020 average (Apr 2).

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 5b in Iowa

473 plants native to the lower 48 states, recorded in Iowa, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.

Trees 49

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °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 °Fbalsam fir60 ft · blooms mid summer · low shade tolerance · to −43 °F

Shrubs 77

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 191

alkali buttercup1 ft · blooms late spring · low 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 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 136

arctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °FBicknell's sedge3 ft · blooms late spring · low shade tolerance · to −38 °Fbig bluestem6 ft · blooms summer · high shade tolerance · to −46 °Fblue grama1 ft · blooms early summer · high shade tolerance · to −43 °F

Vines 7

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 honeysuckle16 ft · blooms late summer · low shade tolerance · to −33 °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 Modale, IA.

Soil in Modale, IA

The soil mapped at the center of ZIP 51556 is Salix — silty clay loam, moderately well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH7.0neutral; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter3.5%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Salix 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 51556; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Modale, IA

Summer high86 °Faverage high, July
Winter low13 °Faverage low, January
Hot days23days a year at 90 °F or more
Freezing nights143nights a year at 32 °F or less
Growing degree days3,305base 50 °F — the season’s usable heat
Longest day15 h 12 mindaylight on June 21
Shortest day9 h 09 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation28.3 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 31 °F, low 13 °F 31°13° JanFebruary: average high 37 °F, low 17 °F 37°17° FebMarch: average high 50 °F, low 27 °F 50°27° MarApril: average high 62 °F, low 38 °F 62°38° AprMay: average high 73 °F, low 50 °F 73°50° MayJune: average high 82 °F, low 60 °F 82°60° JunJuly: average high 86 °F, low 65 °F 86°65° JulAugust: average high 83 °F, low 63 °F 83°63° AugSeptember: average high 77 °F, low 54 °F 77°54° SepOctober: average high 65 °F, low 41 °F 65°41° OctNovember: average high 49 °F, low 28 °F 49°28° NovDecember: average high 36 °F, low 18 °F 36°18° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 0.51 in precipitation 0.5 JanFebruary: 0.62 in precipitation 0.6 FebMarch: 1.50 in precipitation 1.5 MarApril: 3.13 in precipitation 3.1 AprMay: 3.95 in precipitation 4.0 MayJune: 4.64 in precipitation 4.6 JunJuly: 3.05 in precipitation 3.0 JulAugust: 3.47 in precipitation 3.5 AugSeptember: 3.24 in precipitation 3.2 SepOctober: 2.01 in precipitation 2.0 OctNovember: 1.25 in precipitation 1.3 NovDecember: 0.89 in precipitation 0.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Blair, NE (8 mi away); precipitation: Tekamah Municipal Airport, NE (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

515575b
Mondamin, IA · 7 mi
515555b
Missouri Valley, IA · 9 mi
515505b
Magnolia, IA · 9 mi
680085b
Blair, NE · 10 mi
680295b
Herman, NE · 12 mi
680235b
Fort Calhoun, NE · 12 mi
515645b
Pisgah, IA · 13 mi
515465b
Logan, IA · 14 mi

Iowa planting zones →

Questions about 51556

What planting zone is ZIP code 51556?

ZIP code 51556 (Modale, IA) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Modale, IA?

The median last spring frost (32 °F) near 51556 is April 22; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Blair station.

When is the first frost in Modale, IA?

The median first fall frost near 51556 is October 17, giving a median frost-free growing season of 177 days.

When should I plant tomatoes in 51556?

Start tomato seeds indoors around Feb 25 – Mar 11 and set transplants outside around Apr 29 – May 13, one to three weeks after the median last frost.

How much rain and snow does 51556 get?

About 28.3 inches of precipitation a year (NOAA 1991–2020 normals, Tekamah Municipal Airport station).

How hot do summers get in Modale, IA?

The average high peaks at 86 °F in July, with about 23 days a year at 90 °F or more.

What kind of soil does 51556 have?

The USDA soil survey maps Salix at the center of ZIP 51556: silty clay loam, moderately well drained, pH about 7.0 (neutral).

Did spring come early in Modale, IA in 2026?

Spring leaf-out near 51556 came on Mar 11 in 2026, 22 days earlier than the 1991–2020 average (Apr 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Modale, IA?

Long-day onions: the longest day near 51556 is 15 h 12 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).