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

Planting zone for 50028 — Baxter, IA

ZIP code 50028 (Baxter, Jasper 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 50028 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 zone5a

Was 5a on the 2012 map — half a zone warmer now. 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 Baxter, 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 Baxter, 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 4only 10% chance of frost after

First fall frostOctober 17median — 10% chance by Oct 1

Growing season174 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 12 and returns around October 26.

From the NOAA station Newton, IA — 9 miles away, elevation 961 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 50028

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 50028 came on Mar 25 — 12 days earlier than the 1991–2020 average (Apr 6).

average
Apr 62026
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 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 Baxter, IA.

Soil in Baxter, IA

The soil mapped at the center of ZIP 50028 is Ackmore — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables

pH5.9moderately acidic; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter2%moderate

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classPrime farmland if drainedUSDA classification

Map unit: Ackmore-Colo complex, 2 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 50028; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Baxter, IA

Summer high85 °Faverage high, July

Winter low10 °Faverage low, January

Hot days21days a year at 90 °F or more

Freezing nights142nights a year at 32 °F or less

Growing degree days3,112base 50 °F — the season’s usable heat

Longest day15 h 13 mindaylight on June 21

Shortest day9 h 08 mindaylight on December 21

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

Precipitation35.1 inper year, rain and melted snow

Snowfall29 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Newton, IA (9 mi away); precipitation: Newton, IA (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

Melbourne, IA · 10 mi

501415b

Laurel, IA · 11 mi

Iowa planting zones →

Questions about 50028

What planting zone is ZIP code 50028?

ZIP code 50028 (Baxter, 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 Baxter, IA?

The median last spring frost (32 °F) near 50028 is April 22; after May 4 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Newton station.

When is the first frost in Baxter, IA?

The median first fall frost near 50028 is October 17, giving a median frost-free growing season of 174 days.

When should I plant tomatoes in 50028?

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 50028 get?

About 35.1 inches of precipitation a year and 29 inches of snowfall (NOAA 1991–2020 normals, Newton station).

How hot do summers get in Baxter, IA?

The average high peaks at 85 °F in July, with about 21 days a year at 90 °F or more.

What kind of soil does 50028 have?

The USDA soil survey maps Ackmore at the center of ZIP 50028: silt loam, somewhat poorly drained, pH about 5.9 (moderately acidic).

Did spring come early in Baxter, IA in 2026?

Spring leaf-out near 50028 came on Mar 25 in 2026, 12 days earlier than the 1991–2020 average (Apr 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Baxter, IA?

Long-day onions: the longest day near 50028 is 15 h 13 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 50028 change?

Yes. The 2012 USDA map put 50028 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.