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

Planting zone for 52566 — Kirkville, IA

ZIP code 52566 (Kirkville, Wapello County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 23 and the first fall frost October 14.

Where ZIP 52566 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 23

First frostOct 14

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 Kirkville, 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 Kirkville, 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 7only 10% chance of frost after

First fall frostOctober 14median — 10% chance by Sep 29

Growing season172 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 13 and returns around October 24.

From the NOAA station Ottumwa Industrial Airport, IA — 3 miles away, elevation 843 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 52566

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 52566 came on Mar 19 — 13 days earlier than the 1991–2020 average (Apr 1).

average
Apr 12026
Mar 19

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.

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 Kirkville, IA.

Soil in Kirkville, IA

The soil mapped at the center of ZIP 52566 is Coal Palace — silty clay loam, well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up

pH5.6moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2.5%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Coal Palace silty clay loam, 0 to 5 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 52566; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Kirkville, IA

Summer high86 °Faverage high, July

Winter low14 °Faverage low, January

Hot days19days a year at 90 °F or more

Freezing nights131nights a year at 32 °F or less

Growing degree days3,359base 50 °F — the season’s usable heat

Longest day15 h 08 mindaylight on June 21

Shortest day9 h 12 mindaylight on December 21

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

Precipitation37 inper year, rain and melted snow

Snowfall24 inper year; 38 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: Ottumwa Industrial Airport, IA (3 mi away); precipitation: Ottumwa Industrial Airport, IA (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

525485b

Chillicothe, IA · 3 mi

University Park, IA · 12 mi

525775b

Oskaloosa, IA · 13 mi

Iowa planting zones →

Questions about 52566

What planting zone is ZIP code 52566?

ZIP code 52566 (Kirkville, 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 Kirkville, IA?

The median last spring frost (32 °F) near 52566 is April 23; after May 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Ottumwa Industrial Airport station.

When is the first frost in Kirkville, IA?

The median first fall frost near 52566 is October 14, giving a median frost-free growing season of 172 days.

When should I plant tomatoes in 52566?

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 52566 get?

About 37 inches of precipitation a year and 24 inches of snowfall (NOAA 1991–2020 normals, Ottumwa Industrial Airport station).

How hot do summers get in Kirkville, IA?

The average high peaks at 86 °F in July, with about 19 days a year at 90 °F or more.

What kind of soil does 52566 have?

The USDA soil survey maps Coal Palace at the center of ZIP 52566: silty clay loam, well drained, pH about 5.6 (moderately acidic).

Did spring come early in Kirkville, IA in 2026?

Spring leaf-out near 52566 came on Mar 19 in 2026, 13 days earlier than the 1991–2020 average (Apr 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Kirkville, IA?

Long-day onions: the longest day near 52566 is 15 h 08 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).