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

Planting zone for 50152 — Luther, IA

ZIP code 50152 (Luther, Boone County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 23 and the first fall frost October 14.

Where ZIP 50152 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostApr 23
First frostOct 14
2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Luther, 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 Luther, IA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 23median — 50% chance of a later frost
Safe for tender plantsMay 5only 10% chance of frost after
First fall frostOctober 14median — 10% chance by Sep 29
Growing season173 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 11 and returns around October 24.

From the NOAA station Ames 8 Wsw, IA — 4 miles away, elevation 1,099 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 50152

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 12 – Mar 26
SpinachSow outdoors · Mar 12 – Apr 2
Broccoli, cabbageStart indoors · Feb 12 – Feb 26
Broccoli, cabbageTransplant · Apr 2 – Apr 16
Onion setsPlant outdoors · Mar 26 – Apr 9
PotatoesPlant outdoors · Apr 2 – Apr 16
LettuceSow outdoors · Mar 26 – Apr 9
Carrots, beetsSow outdoors · Apr 2 – Apr 16
TomatoesStart indoors · Feb 26 – Mar 12
TomatoesTransplant · Apr 30 – May 14
Peppers, eggplantStart indoors · Feb 12 – Feb 26
Peppers, eggplantTransplant · May 7 – May 21
BeansSow outdoors · Apr 30 – May 14
Sweet cornSow outdoors · Apr 30 – May 14
Cucumbers, squashSow outdoors · Apr 30 – May 14
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 (Apr 23) 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 50152 came on Mar 25 — 13 days earlier than the 1991–2020 average (Apr 7).

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 5a in Iowa

461 plants native to the lower 48 states, recorded in Iowa, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 46

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 185

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 133

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 Luther, IA.

Soil in Luther, IA

The soil mapped at the center of ZIP 50152 is Canisteo — clay loam, poorly drained.

TextureClay loamholds water and nutrients; slow to drain and warm up
pH7.5slightly alkaline; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter7%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Canisteo clay loam, Bemis moraine, 0 to 2 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 50152; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Luther, IA

Summer high84 °Faverage high, July
Winter low12 °Faverage low, January
Hot days15days a year at 90 °F or more
Freezing nights141nights a year at 32 °F or less
Growing degree days3,235base 50 °F — the season’s usable heat
Longest day15 h 14 mindaylight on June 21
Shortest day9 h 07 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation35.9 inper year, rain and melted snow
Snowfall33 inper year; 56 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 29 °F, low 12 °F 29°12° JanFebruary: average high 34 °F, low 16 °F 34°16° FebMarch: average high 48 °F, low 28 °F 48°28° MarApril: average high 62 °F, low 39 °F 62°39° AprMay: average high 73 °F, low 51 °F 73°51° MayJune: average high 81 °F, low 61 °F 81°61° JunJuly: average high 84 °F, low 64 °F 84°64° JulAugust: average high 82 °F, low 62 °F 82°62° AugSeptember: average high 77 °F, low 54 °F 77°54° SepOctober: average high 64 °F, low 41 °F 64°41° OctNovember: average high 48 °F, low 29 °F 48°29° NovDecember: average high 34 °F, low 18 °F 34°18° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 0.69 in precipitation, 7.8 in snowfall 0.7❄8 JanFebruary: 1.02 in precipitation, 10 in snowfall 1.0❄10 FebMarch: 2.01 in precipitation, 4.2 in snowfall 2.0❄4 MarApril: 3.89 in precipitation, 1.3 in snowfall 3.9❄1 AprMay: 4.99 in precipitation 5.0 MayJune: 4.89 in precipitation 4.9 JunJuly: 4.53 in precipitation 4.5 JulAugust: 4.75 in precipitation 4.8 AugSeptember: 3.47 in precipitation 3.5 SepOctober: 2.63 in precipitation, 0.5 in snowfall 2.6❄1 OctNovember: 1.86 in precipitation, 2 in snowfall 1.9❄2 NovDecember: 1.17 in precipitation, 6.9 in snowfall 1.2❄7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Ames 8 Wsw, IA (4 mi away); precipitation: Ames 8 Wsw, IA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

501565b
Madrid, IA · 5 mi
500375a
Boone, IA · 7 mi
500995a
Boone, IA · 7 mi
501345b
Kelley, IA · 8 mi
500365a
Boone, IA · 8 mi
500145b
Ames, IA · 8 mi
500135b
Ames, IA · 9 mi
502765a
Woodward, IA · 9 mi

Iowa planting zones →

Questions about 50152

What planting zone is ZIP code 50152?

ZIP code 50152 (Luther, IA) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Luther, IA?

The median last spring frost (32 °F) near 50152 is April 23; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Ames 8 Wsw station.

When is the first frost in Luther, IA?

The median first fall frost near 50152 is October 14, giving a median frost-free growing season of 173 days.

When should I plant tomatoes in 50152?

Start tomato seeds indoors around Feb 26 – Mar 12 and set transplants outside around Apr 30 – May 14, one to three weeks after the median last frost.

How much rain and snow does 50152 get?

About 35.9 inches of precipitation a year and 33 inches of snowfall (NOAA 1991–2020 normals, Ames 8 Wsw station).

How hot do summers get in Luther, IA?

The average high peaks at 84 °F in July, with about 15 days a year at 90 °F or more.

What kind of soil does 50152 have?

The USDA soil survey maps Canisteo at the center of ZIP 50152: clay loam, poorly drained, pH about 7.5 (slightly alkaline).

Did spring come early in Luther, IA in 2026?

Spring leaf-out near 50152 came on Mar 25 in 2026, 13 days earlier than the 1991–2020 average (Apr 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Luther, IA?

Long-day onions: the longest day near 50152 is 15 h 14 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).