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

Planting zone for 66546 — Wakarusa, KS

ZIP code 66546 (Wakarusa, Shawnee County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 15 and the first fall frost October 21.

Where ZIP 66546 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 15

First frostOct 21

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 Wakarusa, 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 Wakarusa, KS

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 15median — 50% chance of a later frost

Safe for tender plantsApril 30only 10% chance of frost after

First fall frostOctober 21median — 10% chance by Oct 5

Growing season185 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around October 31.

From the NOAA station Topeka Forbes Field, KS — 5 miles away, elevation 1,066 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 66546

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 4 – Mar 18

SpinachSow outdoors · Mar 4 – Mar 25

Broccoli, cabbageStart indoors · Feb 4 – Feb 18

Broccoli, cabbageTransplant · Mar 25 – Apr 8

Onion setsPlant outdoors · Mar 18 – Apr 1

PotatoesPlant outdoors · Mar 25 – Apr 8

LettuceSow outdoors · Mar 18 – Apr 1

Carrots, beetsSow outdoors · Mar 25 – Apr 8

TomatoesStart indoors · Feb 18 – Mar 4

TomatoesTransplant · Apr 22 – May 6

Peppers, eggplantStart indoors · Feb 4 – Feb 18

Peppers, eggplantTransplant · Apr 29 – May 13

BeansSow outdoors · Apr 22 – May 6

Sweet cornSow outdoors · Apr 22 – May 6

Cucumbers, squashSow outdoors · Apr 22 – May 6

Fall lettuce, spinachSow outdoors · Aug 26 – Sep 9

GarlicPlant cloves · Oct 7 – Nov 11

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 15) and first fall frost (Oct 21) 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 66546 came on Feb 25 — 20 days earlier than the 1991–2020 average (Mar 17).

average
Mar 172026
Feb 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).

Soil in Wakarusa, KS

The soil mapped at the center of ZIP 66546 is Martin — silty clay loam, moderately well drained.

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

pH6.1slightly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter3.7%moderate

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classprime farmlandUSDA classification

Map unit: Martin silty clay loam, 3 to 7 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 66546; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Wakarusa, KS

Summer high91 °Faverage high, July

Winter low19 °Faverage low, January

Hot days52days a year at 90 °F or more

Freezing nights117nights a year at 32 °F or less

Growing degree days4,183base 50 °F — the season’s usable heat

Longest day14 h 54 mindaylight on June 21

Shortest day9 h 26 mindaylight on December 21

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

Precipitation37.6 inper year, rain and melted snow

Snowfall12 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Topeka Forbes Field, KS (5 mi away); precipitation: Auburn, KS (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

666196b

Topeka, KS · 4 mi

664146b

Carbondale, KS · 5 mi

Kansas planting zones →

Questions about 66546

What planting zone is ZIP code 66546?

ZIP code 66546 (Wakarusa, 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 Wakarusa, KS?

The median last spring frost (32 °F) near 66546 is April 15; after April 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Topeka Forbes Field station.

When is the first frost in Wakarusa, KS?

The median first fall frost near 66546 is October 21, giving a median frost-free growing season of 185 days.

When should I plant tomatoes in 66546?

Start tomato seeds indoors around Feb 18 – Mar 4 and set transplants outside around Apr 22 – May 6, one to three weeks after the median last frost.

How much rain and snow does 66546 get?

About 37.6 inches of precipitation a year and 12 inches of snowfall (NOAA 1991–2020 normals, Auburn station).

How hot do summers get in Wakarusa, KS?

The average high peaks at 91 °F in July, with about 52 days a year at 90 °F or more.

What kind of soil does 66546 have?

The USDA soil survey maps Martin at the center of ZIP 66546: silty clay loam, moderately well drained, pH about 6.1 (slightly acidic).

Did spring come early in Wakarusa, KS in 2026?

Spring leaf-out near 66546 came on Feb 25 in 2026, 20 days earlier than the 1991–2020 average (Mar 17), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Wakarusa, KS?

Intermediate onions: the longest day near 66546 is 14 h 54 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 66546 change?

Yes. The 2012 USDA map put 66546 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.