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

Planting zone for 66548 — Waterville, KS

ZIP code 66548 (Waterville, Marshall County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 25 and the first fall frost October 13.

Where ZIP 66548 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.

Zone6a−10 to −5 °F

Coldest night−23.3 to −20.6 °C

Last frostApr 25

First frostOct 13

2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Waterville, 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 Waterville, KS

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 25median — 50% chance of a later frost

Safe for tender plantsMay 9only 10% chance of frost after

First fall frostOctober 13median — 10% chance by Sep 28

Growing season171 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 14 and returns around October 22.

From the NOAA station Marysville, KS — 14 miles away, elevation 1,178 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 66548

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 14 – Mar 28

SpinachSow outdoors · Mar 14 – Apr 4

Broccoli, cabbageStart indoors · Feb 14 – Feb 28

Broccoli, cabbageTransplant · Apr 4 – Apr 18

Onion setsPlant outdoors · Mar 28 – Apr 11

PotatoesPlant outdoors · Apr 4 – Apr 18

LettuceSow outdoors · Mar 28 – Apr 11

Carrots, beetsSow outdoors · Apr 4 – Apr 18

TomatoesStart indoors · Feb 28 – Mar 14

TomatoesTransplant · May 2 – May 16

Peppers, eggplantStart indoors · Feb 14 – Feb 28

Peppers, eggplantTransplant · May 9 – May 23

BeansSow outdoors · May 2 – May 16

Sweet cornSow outdoors · May 2 – May 16

Cucumbers, squashSow outdoors · May 2 – May 16

Fall lettuce, spinachSow outdoors · Aug 18 – Sep 1

GarlicPlant cloves · Sep 29 – Nov 3

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 25) and first fall frost (Oct 13) 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 66548 came on Mar 7 — 15 days earlier than the 1991–2020 average (Mar 22).

average
Mar 222026
Mar 7

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 6a in Kansas

425 plants native to the lower 48 states, recorded in Kansas, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. 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 Waterville, KS.

Soil in Waterville, KS

The soil mapped at the center of ZIP 66548 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 66548; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Waterville, KS

Summer high90 °Faverage high, July

Winter low15 °Faverage low, January

Hot days46days a year at 90 °F or more

Freezing nights135nights a year at 32 °F or less

Growing degree days3,897base 50 °F — the season’s usable heat

Longest day14 h 59 mindaylight on June 21

Shortest day9 h 21 mindaylight on December 21

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

Precipitation33.1 inper year, rain and melted snow

Snowfall13 inper year; 19 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Marysville, KS (14 mi away); precipitation: Blue Rapids, KS (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

669336a

Barnes, KS · 6 mi

664116a

Blue Rapids, KS · 7 mi

669436a

Greenleaf, KS · 11 mi

665546a

Randolph, KS · 12 mi

665086a

Marysville, KS · 14 mi

Kansas planting zones →

Questions about 66548

What planting zone is ZIP code 66548?

ZIP code 66548 (Waterville, KS) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Waterville, KS?

The median last spring frost (32 °F) near 66548 is April 25; after May 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Marysville station.

When is the first frost in Waterville, KS?

The median first fall frost near 66548 is October 13, giving a median frost-free growing season of 171 days.

When should I plant tomatoes in 66548?

Start tomato seeds indoors around Feb 28 – Mar 14 and set transplants outside around May 2 – May 16, one to three weeks after the median last frost.

How much rain and snow does 66548 get?

About 33.1 inches of precipitation a year and 13 inches of snowfall (NOAA 1991–2020 normals, Blue Rapids station).

How hot do summers get in Waterville, KS?

The average high peaks at 90 °F in July, with about 46 days a year at 90 °F or more.

What kind of soil does 66548 have?

The USDA soil survey maps Pawnee at the center of ZIP 66548: clay loam, moderately well drained, pH about 5.6 (moderately acidic).

Did spring come early in Waterville, KS in 2026?

Spring leaf-out near 66548 came on Mar 7 in 2026, 15 days earlier than the 1991–2020 average (Mar 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Waterville, KS?

Intermediate onions: the longest day near 66548 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 66548 change?

Yes. The 2012 USDA map put 66548 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.