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

Planting zone for 66868 — Reading, KS

ZIP code 66868 (Reading, Lyon County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 13 and the first fall frost October 26.

Where ZIP 66868 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 13

First frostOct 26

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 Reading, 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 Reading, KS

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 13median — 50% chance of a later frost

Safe for tender plantsApril 28only 10% chance of frost after

First fall frostOctober 26median — 10% chance by Oct 10

Growing season194 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 2 and returns around November 3.

From the NOAA station Osage City, KS — 11 miles away, elevation 1,096 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 66868

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 2 – Mar 16

SpinachSow outdoors · Mar 2 – Mar 23

Broccoli, cabbageStart indoors · Feb 2 – Feb 16

Broccoli, cabbageTransplant · Mar 23 – Apr 6

Onion setsPlant outdoors · Mar 16 – Mar 30

PotatoesPlant outdoors · Mar 23 – Apr 6

LettuceSow outdoors · Mar 16 – Mar 30

Carrots, beetsSow outdoors · Mar 23 – Apr 6

TomatoesStart indoors · Feb 16 – Mar 2

TomatoesTransplant · Apr 20 – May 4

Peppers, eggplantStart indoors · Feb 2 – Feb 16

Peppers, eggplantTransplant · Apr 27 – May 11

BeansSow outdoors · Apr 20 – May 4

Sweet cornSow outdoors · Apr 20 – May 4

Cucumbers, squashSow outdoors · Apr 20 – May 4

Fall lettuce, spinachSow outdoors · Aug 31 – Sep 14

GarlicPlant cloves · Oct 12 – Nov 16

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 13) and first fall frost (Oct 26) 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 66868 came on Feb 24 — 20 days earlier than the 1991–2020 average (Mar 16).

average
Mar 162026
Feb 24

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 Reading, KS

The soil mapped at the center of ZIP 66868 is Elmont — silty clay loam, well drained.

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

pH6.2slightly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Elmont silty clay loam, 3 to 7 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 66868; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Reading, KS

Summer high89 °Faverage high, July

Winter low18 °Faverage low, January

Hot days46days a year at 90 °F or more

Freezing nights124nights a year at 32 °F or less

Growing degree days3,920base 50 °F — the season’s usable heat

Longest day14 h 52 mindaylight on June 21

Shortest day9 h 28 mindaylight on December 21

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

Precipitation36.1 inper year, rain and melted snow

Snowfall16 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Osage City, KS (11 mi away); precipitation: Miller 4 Ssw, KS (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

668306b

Admire, KS · 7 mi

665236b

Osage City, KS · 9 mi

668646b

Neosho Rapids, KS · 13 mi

Burlingame, KS · 16 mi

664516b

Lyndon, KS · 17 mi

Kansas planting zones →

Questions about 66868

What planting zone is ZIP code 66868?

ZIP code 66868 (Reading, 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 Reading, KS?

The median last spring frost (32 °F) near 66868 is April 13; after April 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Osage City station.

When is the first frost in Reading, KS?

The median first fall frost near 66868 is October 26, giving a median frost-free growing season of 194 days.

When should I plant tomatoes in 66868?

Start tomato seeds indoors around Feb 16 – Mar 2 and set transplants outside around Apr 20 – May 4, one to three weeks after the median last frost.

How much rain and snow does 66868 get?

About 36.1 inches of precipitation a year and 16 inches of snowfall (NOAA 1991–2020 normals, Miller 4 Ssw station).

How hot do summers get in Reading, KS?

The average high peaks at 89 °F in July, with about 46 days a year at 90 °F or more.

What kind of soil does 66868 have?

The USDA soil survey maps Elmont at the center of ZIP 66868: silty clay loam, well drained, pH about 6.2 (slightly acidic).

Did spring come early in Reading, KS in 2026?

Spring leaf-out near 66868 came on Feb 24 in 2026, 20 days earlier than the 1991–2020 average (Mar 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Reading, KS?

Intermediate onions: the longest day near 66868 is 14 h 52 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 66868 change?

Yes. The 2012 USDA map put 66868 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.