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

Planting zone for 66609 — Topeka, KS

ZIP code 66609 (Topeka, 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 66609 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 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 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 — 2 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 66609

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 66609 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

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Fbitternut hickory75 ft · blooms mid spring · high shade tolerance · to −47 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fblack maple100 ft · blooms late spring · low shade tolerance · to −47 °F

Shrubs 64

alderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fblack cherry80 ft · blooms late spring · high shade tolerance · to −33 °Fblackhaw16 ft · blooms spring · low shade tolerance · to −33 °Fblackjack oak25 ft · blooms mid spring · high shade tolerance · to −13 °F

Wildflowers & perennials 176

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °FAmerican speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °F

Grasses 134

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °FBicknell's sedge3 ft · blooms late spring · low shade tolerance · to −38 °Fbig bluestem6 ft · blooms summer · high shade tolerance · to −46 °F

Vines 11

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °Fheartleaf peppervine2 ft · blooms late spring · low shade tolerance · to −8 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °F

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 66609 is Pawnee — clay loam, moderately well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up
pH5.6moderately acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter2%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Pawnee clay loam, 4 to 8 percent slopes, eroded.

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 66609; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Topeka, 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
Precipitation36.7 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 41 °F, low 19 °F 41°19° JanFebruary: average high 46 °F, low 23 °F 46°23° FebMarch: average high 57 °F, low 33 °F 57°33° MarApril: average high 67 °F, low 43 °F 67°43° AprMay: average high 76 °F, low 54 °F 76°54° MayJune: average high 86 °F, low 64 °F 86°64° JunJuly: average high 91 °F, low 69 °F 91°69° JulAugust: average high 90 °F, low 66 °F 90°66° AugSeptember: average high 81 °F, low 57 °F 81°57° SepOctober: average high 69 °F, low 45 °F 69°45° OctNovember: average high 55 °F, low 33 °F 55°33° NovDecember: average high 44 °F, low 23 °F 44°23° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 0.80 in precipitation 0.8 JanFebruary: 1.23 in precipitation 1.2 FebMarch: 2.28 in precipitation 2.3 MarApril: 3.94 in precipitation 3.9 AprMay: 5.18 in precipitation 5.2 MayJune: 4.74 in precipitation 4.7 JunJuly: 4.56 in precipitation 4.6 JulAugust: 4.45 in precipitation 4.5 AugSeptember: 3.46 in precipitation 3.5 SepOctober: 2.83 in precipitation 2.8 OctNovember: 1.81 in precipitation 1.8 NovDecember: 1.39 in precipitation 1.4 Dec

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

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

666056b
Topeka, KS · 3 mi
666196b
Topeka, KS · 3 mi
666116b
Topeka, KS · 3 mi
666216b
Topeka, KS · 4 mi
666126b
Topeka, KS · 4 mi
666076b
Topeka, KS · 5 mi
666226b
Topeka, KS · 5 mi
666016b
Topeka, KS · 5 mi

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

Questions about 66609

What planting zone is ZIP code 66609?

ZIP code 66609 (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 66609 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 Topeka, KS?

The median first fall frost near 66609 is October 21, giving a median frost-free growing season of 185 days.

When should I plant tomatoes in 66609?

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 66609 get?

About 36.7 inches of precipitation a year (NOAA 1991–2020 normals, Topeka Forbes Field station).

How hot do summers get in Topeka, 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 66609 have?

The USDA soil survey maps Pawnee at the center of ZIP 66609: clay loam, moderately well drained, pH about 5.6 (moderately acidic).

Did spring come early in Topeka, KS in 2026?

Spring leaf-out near 66609 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 66609 is 14 h 54 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 66609 change?

Yes. The 2012 USDA map put 66609 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.