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

Planting zone for 57024 — Egan, SD

ZIP code 57024 (Egan, Moody County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 5 and the first fall frost October 1.

Where ZIP 57024 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.

Zone4b−25 to −20 °F

Coldest night−31.7 to −28.9 °C

Last frostMay 5

First frostOct 1

2012 zone4b

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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Egan, SD…

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 Egan, SD

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 5median — 50% chance of a later frost

Safe for tender plantsMay 17only 10% chance of frost after

First fall frostOctober 1median — 10% chance by Sep 19

Growing season148 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 26 and returns around October 11.

From the NOAA station Flandreau, SD — 6 miles away, elevation 1,568 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 57024

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 24 – Apr 7

SpinachSow outdoors · Mar 24 – Apr 14

Broccoli, cabbageStart indoors · Feb 24 – Mar 10

Broccoli, cabbageTransplant · Apr 14 – Apr 28

Onion setsPlant outdoors · Apr 7 – Apr 21

PotatoesPlant outdoors · Apr 14 – Apr 28

LettuceSow outdoors · Apr 7 – Apr 21

Carrots, beetsSow outdoors · Apr 14 – Apr 28

TomatoesStart indoors · Mar 10 – Mar 24

TomatoesTransplant · May 12 – May 26

Peppers, eggplantStart indoors · Feb 24 – Mar 10

Peppers, eggplantTransplant · May 19 – Jun 2

BeansSow outdoors · May 12 – May 26

Sweet cornSow outdoors · May 12 – May 26

Cucumbers, squashSow outdoors · May 12 – May 26

Fall lettuce, spinachSow outdoors · Aug 6 – Aug 20

GarlicPlant cloves · Sep 17 – Oct 22

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 5) and first fall frost (Oct 1) 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 57024 came on Mar 28 — 20 days earlier than the 1991–2020 average (Apr 17).

average
Apr 172026
Mar 28

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 4b in South Dakota

430 plants native to the lower 48 states, recorded in South Dakota, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. 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 Egan, SD.

Soil in Egan, SD

The soil mapped at the center of ZIP 57024 is Dimo — clay loam, somewhat poorly drained.

TextureClay loamholds water and nutrients; slow to drain and warm up

pH6.5neutral; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter5%high

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Dimo 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 57024; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Egan, SD

Summer high81 °Faverage high, July

Winter low4 °Faverage low, January

Hot days9days a year at 90 °F or more

Freezing nights177nights a year at 32 °F or less

Growing degree days2,376base 50 °F — the season’s usable heat

Longest day15 h 29 mindaylight on June 21

Shortest day8 h 53 mindaylight on December 21

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

Precipitation28.5 inper year, rain and melted snow

Snowfall40 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Flandreau, SD (6 mi away); precipitation: Flandreau, SD (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4b.

Dell Rapids, SD · 9 mi

570754b

Wentworth, SD · 14 mi

South Dakota planting zones →

Questions about 57024

What planting zone is ZIP code 57024?

ZIP code 57024 (Egan, SD) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Egan, SD?

The median last spring frost (32 °F) near 57024 is May 5; after May 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Flandreau station.

When is the first frost in Egan, SD?

The median first fall frost near 57024 is October 1, giving a median frost-free growing season of 148 days.

When should I plant tomatoes in 57024?

Start tomato seeds indoors around Mar 10 – Mar 24 and set transplants outside around May 12 – May 26, one to three weeks after the median last frost.

How much rain and snow does 57024 get?

About 28.5 inches of precipitation a year and 40 inches of snowfall (NOAA 1991–2020 normals, Flandreau station).

How hot do summers get in Egan, SD?

The average high peaks at 81 °F in July, with about 9 days a year at 90 °F or more.

What kind of soil does 57024 have?

The USDA soil survey maps Dimo at the center of ZIP 57024: clay loam, somewhat poorly drained, pH about 6.5 (neutral).

Did spring come early in Egan, SD in 2026?

Spring leaf-out near 57024 came on Mar 28 in 2026, 20 days earlier than the 1991–2020 average (Apr 17), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Egan, SD?

Long-day onions: the longest day near 57024 is 15 h 29 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).