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

Planting zone for 51364 — Terril, IA

ZIP code 51364 (Terril, Dickinson County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 28 and the first fall frost October 11.

Where ZIP 51364 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 28

First frostOct 11

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 Terril, 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 Terril, IA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 28median — 50% chance of a later frost

Safe for tender plantsMay 9only 10% chance of frost after

First fall frostOctober 11median — 10% chance by Sep 27

Growing season164 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 19 and returns around October 21.

From the NOAA station Spirit Lake, IA — 12 miles away, elevation 1,421 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 51364

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 17 – Mar 31

SpinachSow outdoors · Mar 17 – Apr 7

Broccoli, cabbageStart indoors · Feb 17 – Mar 3

Broccoli, cabbageTransplant · Apr 7 – Apr 21

Onion setsPlant outdoors · Mar 31 – Apr 14

PotatoesPlant outdoors · Apr 7 – Apr 21

LettuceSow outdoors · Mar 31 – Apr 14

Carrots, beetsSow outdoors · Apr 7 – Apr 21

TomatoesStart indoors · Mar 3 – Mar 17

TomatoesTransplant · May 5 – May 19

Peppers, eggplantStart indoors · Feb 17 – Mar 3

Peppers, eggplantTransplant · May 12 – May 26

BeansSow outdoors · May 5 – May 19

Sweet cornSow outdoors · May 5 – May 19

Cucumbers, squashSow outdoors · May 5 – May 19

Fall lettuce, spinachSow outdoors · Aug 16 – Aug 30

GarlicPlant cloves · Sep 27 – Nov 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 28) and first fall frost (Oct 11) 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 51364 came on Mar 25 — 21 days earlier than the 1991–2020 average (Apr 15).

average
Apr 152026
Mar 25

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.

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 Terril, IA.

Soil in Terril, IA

The soil mapped at the center of ZIP 51364 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, 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 51364; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Terril, IA

Summer high83 °Faverage high, July

Winter low7 °Faverage low, January

Hot days11days a year at 90 °F or more

Freezing nights149nights a year at 32 °F or less

Growing degree days2,751base 50 °F — the season’s usable heat

Longest day15 h 24 mindaylight on June 21

Shortest day8 h 58 mindaylight on December 21

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

Precipitation29.1 inper year, rain and melted snow

Snowfall42 inper year; 73 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: Spirit Lake, IA (12 mi away); precipitation: Spirit Lake, IA (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

513635a

Superior, IA · 9 mi

513315a

Arnolds Park, IA · 9 mi

513405a

Fostoria, IA · 11 mi

513345a

Estherville, IA · 11 mi

Spirit Lake, IA · 11 mi

513335a

Dickens, IA · 11 mi

Iowa planting zones →

Questions about 51364

What planting zone is ZIP code 51364?

ZIP code 51364 (Terril, 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 Terril, IA?

The median last spring frost (32 °F) near 51364 is April 28; after May 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Spirit Lake station.

When is the first frost in Terril, IA?

The median first fall frost near 51364 is October 11, giving a median frost-free growing season of 164 days.

When should I plant tomatoes in 51364?

Start tomato seeds indoors around Mar 3 – Mar 17 and set transplants outside around May 5 – May 19, one to three weeks after the median last frost.

How much rain and snow does 51364 get?

About 29.1 inches of precipitation a year and 42 inches of snowfall (NOAA 1991–2020 normals, Spirit Lake station).

How hot do summers get in Terril, IA?

The average high peaks at 83 °F in July, with about 11 days a year at 90 °F or more.

What kind of soil does 51364 have?

The USDA soil survey maps Canisteo at the center of ZIP 51364: clay loam, poorly drained, pH about 7.5 (slightly alkaline).

Did spring come early in Terril, IA in 2026?

Spring leaf-out near 51364 came on Mar 25 in 2026, 21 days earlier than the 1991–2020 average (Apr 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Terril, IA?

Long-day onions: the longest day near 51364 is 15 h 24 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).