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

Planting zone for 66624 — Topeka, KS

ZIP code 66624 (Topeka, Shawnee County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 16 and the first fall frost October 22.

Where ZIP 66624 is

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 16
First frostOct 22
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

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Loading the forecast for Topeka, 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 Topeka, KS

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 16median — 50% chance of a later frost
Safe for tender plantsApril 27only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 6
Growing season189 daysfrost-free, median

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

From the NOAA station Topeka - NWS, KS — 7 miles away, elevation 879 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 66624

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 5 – Mar 19
SpinachSow outdoors · Mar 5 – Mar 26
Broccoli, cabbageStart indoors · Feb 5 – Feb 19
Broccoli, cabbageTransplant · Mar 26 – Apr 9
Onion setsPlant outdoors · Mar 19 – Apr 2
PotatoesPlant outdoors · Mar 26 – Apr 9
LettuceSow outdoors · Mar 19 – Apr 2
Carrots, beetsSow outdoors · Mar 26 – Apr 9
TomatoesStart indoors · Feb 19 – Mar 5
TomatoesTransplant · Apr 23 – May 7
Peppers, eggplantStart indoors · Feb 5 – Feb 19
Peppers, eggplantTransplant · Apr 30 – May 14
BeansSow outdoors · Apr 23 – May 7
Sweet cornSow outdoors · Apr 23 – May 7
Cucumbers, squashSow outdoors · Apr 23 – May 7
Fall lettuce, spinachSow outdoors · Aug 27 – Sep 10
GarlicPlant cloves · Oct 8 – Nov 12
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 16) and first fall frost (Oct 22) 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 66624 came on Feb 25 — 20 days earlier than the 1991–2020 average (Mar 17).

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.

Trees 37

Shrubs 64

Wildflowers & perennials 176

Grasses 134

Vines 11

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 Topeka, KS.

Soil in Topeka, KS

The soil mapped at the center of ZIP 66624 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 classFarmland of statewide importanceUSDA classification

Map unit: Martin silty clay loam, 7 to 12 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 66624; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Topeka, KS

Summer high89 °Faverage high, July
Winter low19 °Faverage low, January
Hot days44days a year at 90 °F or more
Freezing nights114nights a year at 32 °F or less
Growing degree days4,038base 50 °F — the season’s usable heat
Longest day14 h 55 mindaylight on June 21
Shortest day9 h 25 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation37.9 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 40 °F, low 19 °F 40°19° JanFebruary: average high 45 °F, low 23 °F 45°23° FebMarch: average high 56 °F, low 33 °F 56°33° MarApril: average high 67 °F, low 43 °F 67°43° AprMay: average high 76 °F, low 55 °F 76°55° MayJune: average high 85 °F, low 64 °F 85°64° JunJuly: average high 89 °F, low 68 °F 89°68° JulAugust: average high 87 °F, low 66 °F 87°66° AugSeptember: average high 80 °F, low 57 °F 80°57° SepOctober: average high 69 °F, low 44 °F 69°44° OctNovember: average high 55 °F, low 32 °F 55°32° NovDecember: average high 43 °F, low 23 °F 43°23° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 0.93 in precipitation 0.9 JanFebruary: 1.36 in precipitation 1.4 FebMarch: 2.39 in precipitation 2.4 MarApril: 3.84 in precipitation 3.8 AprMay: 5.42 in precipitation 5.4 MayJune: 5.27 in precipitation 5.3 JunJuly: 4.30 in precipitation 4.3 JulAugust: 4.25 in precipitation 4.3 AugSeptember: 3.81 in precipitation 3.8 SepOctober: 2.86 in precipitation 2.9 OctNovember: 2.11 in precipitation 2.1 NovDecember: 1.37 in precipitation 1.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Topeka - NWS, KS (7 mi away); precipitation: Topeka 2.1 Wsw, KS (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

All 31 ZIP codes in Topeka → · Kansas planting zones →

Questions about 66624

What planting zone is ZIP code 66624?

ZIP code 66624 (Topeka, 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 Topeka, KS?

The median last spring frost (32 °F) near 66624 is April 16; after April 27 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Topeka - NWS station.

When is the first frost in Topeka, KS?

The median first fall frost near 66624 is October 22, giving a median frost-free growing season of 189 days.

When should I plant tomatoes in 66624?

Start tomato seeds indoors around Feb 19 – Mar 5 and set transplants outside around Apr 23 – May 7, one to three weeks after the median last frost.

How much rain and snow does 66624 get?

About 37.9 inches of precipitation a year (NOAA 1991–2020 normals, Topeka 2.1 Wsw station).

How hot do summers get in Topeka, KS?

The average high peaks at 89 °F in July, with about 44 days a year at 90 °F or more.

What kind of soil does 66624 have?

The USDA soil survey maps Martin at the center of ZIP 66624: silty clay loam, moderately well drained, pH about 6.1 (slightly acidic).

Did spring come early in Topeka, KS in 2026?

Spring leaf-out near 66624 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 Topeka, KS?

Intermediate onions: the longest day near 66624 is 14 h 55 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 66624 change?

Yes. The 2012 USDA map put 66624 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.