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

Planting zone for 67478 — Simpson, KS

ZIP code 67478 (Simpson, Mitchell County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 19 and the first fall frost October 19.

Where ZIP 67478 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.

Zone6b−5 to 0 °F

Coldest night−20.6 to −17.8 °C

Last frostApr 19

First frostOct 19

2012 zone6a

Was 6a 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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Simpson, KS…

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 Simpson, KS

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 19median — 50% chance of a later frost

Safe for tender plantsMay 2only 10% chance of frost after

First fall frostOctober 19median — 10% chance by Oct 4

Growing season181 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 8 and returns around October 27.

From the NOAA station Beloit, KS — 10 miles away, elevation 1,391 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 67478

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 8 – Mar 22

SpinachSow outdoors · Mar 8 – Mar 29

Broccoli, cabbageStart indoors · Feb 8 – Feb 22

Broccoli, cabbageTransplant · Mar 29 – Apr 12

Onion setsPlant outdoors · Mar 22 – Apr 5

PotatoesPlant outdoors · Mar 29 – Apr 12

LettuceSow outdoors · Mar 22 – Apr 5

Carrots, beetsSow outdoors · Mar 29 – Apr 12

TomatoesStart indoors · Feb 22 – Mar 8

TomatoesTransplant · Apr 26 – May 10

Peppers, eggplantStart indoors · Feb 8 – Feb 22

Peppers, eggplantTransplant · May 3 – May 17

BeansSow outdoors · Apr 26 – May 10

Sweet cornSow outdoors · Apr 26 – May 10

Cucumbers, squashSow outdoors · Apr 26 – May 10

Fall lettuce, spinachSow outdoors · Aug 24 – Sep 7

GarlicPlant cloves · Oct 5 – Nov 9

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Oct 19) 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 67478 came on Feb 28 — 19 days earlier than the 1991–2020 average (Mar 19).

average
Mar 192026
Feb 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 6b in Kansas

431 plants native to the lower 48 states, recorded in Kansas, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 Simpson, KS.

Soil in Simpson, KS

The soil mapped at the center of ZIP 67478 is McCook — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH7.8slightly alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupBwater soaks in moderately

Farmland classprime farmlandUSDA classification

Map unit: McCook silt loam, rarely flooded.

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 67478; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Simpson, KS

Summer high92 °Faverage high, July

Winter low17 °Faverage low, January

Hot days57days a year at 90 °F or more

Freezing nights131nights a year at 32 °F or less

Growing degree days4,070base 50 °F — the season’s usable heat

Longest day14 h 57 mindaylight on June 21

Shortest day9 h 23 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation29.6 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Beloit, KS (10 mi away); precipitation: Glasco, KS (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Jamestown, KS · 16 mi

669636a

Randall, KS · 18 mi

669016b

Concordia, KS · 20 mi

674676b

Minneapolis, KS · 22 mi

Kansas planting zones →

Questions about 67478

What planting zone is ZIP code 67478?

ZIP code 67478 (Simpson, KS) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Simpson, KS?

The median last spring frost (32 °F) near 67478 is April 19; after May 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Beloit station.

When is the first frost in Simpson, KS?

The median first fall frost near 67478 is October 19, giving a median frost-free growing season of 181 days.

When should I plant tomatoes in 67478?

Start tomato seeds indoors around Feb 22 – Mar 8 and set transplants outside around Apr 26 – May 10, one to three weeks after the median last frost.

How much rain and snow does 67478 get?

About 29.6 inches of precipitation a year (NOAA 1991–2020 normals, Glasco station).

How hot do summers get in Simpson, KS?

The average high peaks at 92 °F in July, with about 57 days a year at 90 °F or more.

What kind of soil does 67478 have?

The USDA soil survey maps McCook at the center of ZIP 67478: silt loam, well drained, pH about 7.8 (slightly alkaline).

Did spring come early in Simpson, KS in 2026?

Spring leaf-out near 67478 came on Feb 28 in 2026, 19 days earlier than the 1991–2020 average (Mar 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Simpson, KS?

Intermediate onions: the longest day near 67478 is 14 h 57 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 67478 change?

Yes. The 2012 USDA map put 67478 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.