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

Planting zone for 66048 — Leavenworth, KS

ZIP code 66048 (Leavenworth, Leavenworth County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 19 and the first fall frost October 19.

Where ZIP 66048 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 19
First frostOct 19
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 Leavenworth, 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 Leavenworth, KS

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 19median — 50% chance of a later frost
Safe for tender plantsMay 4only 10% chance of frost after
First fall frostOctober 19median — 10% chance by Oct 2
Growing season181 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 9 and returns around October 27.

From the NOAA station Leavenworth 3sw, KS — 2 miles away, elevation 873 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 66048

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 8 – Mar 22
SpinachSow outdoors · Mar 8 – Mar 29
Broccoli, cabbageStart indoors · Feb 8 – Feb 22
Broccoli, cabbageTransplant · Mar 29 – Apr 12
Onion setsPlant outdoors · Mar 22 – Apr 5
PotatoesPlant outdoors · Mar 29 – Apr 12
LettuceSow outdoors · Mar 22 – Apr 5
Carrots, beetsSow outdoors · Mar 29 – Apr 12
TomatoesStart indoors · Feb 22 – Mar 8
TomatoesTransplant · Apr 26 – May 10
Peppers, eggplantStart indoors · Feb 8 – Feb 22
Peppers, eggplantTransplant · May 3 – May 17
BeansSow outdoors · Apr 26 – May 10
Sweet cornSow outdoors · Apr 26 – May 10
Cucumbers, squashSow outdoors · Apr 26 – May 10
Fall lettuce, spinachSow outdoors · Aug 24 – Sep 7
GarlicPlant cloves · Oct 5 – Nov 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Oct 19) 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 66048 came on Feb 25 — 21 days earlier than the 1991–2020 average (Mar 18).

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 Leavenworth, KS

The soil mapped at the center of ZIP 66048 is Sharpsburg — 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%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Sharpsburg silty 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 66048; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Leavenworth, KS

Summer high87 °Faverage high, July
Winter low15 °Faverage low, January
Hot days30days a year at 90 °F or more
Freezing nights137nights a year at 32 °F or less
Growing degree days3,647base 50 °F — the season’s usable heat
Longest day14 h 56 mindaylight on June 21
Shortest day9 h 24 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation39.1 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 38 °F, low 15 °F 38°15° JanFebruary: average high 43 °F, low 20 °F 43°20° FebMarch: average high 55 °F, low 29 °F 55°29° MarApril: average high 65 °F, low 41 °F 65°41° AprMay: average high 74 °F, low 51 °F 74°51° MayJune: average high 83 °F, low 62 °F 83°62° JunJuly: average high 87 °F, low 66 °F 87°66° JulAugust: average high 86 °F, low 64 °F 86°64° AugSeptember: average high 79 °F, low 55 °F 79°55° SepOctober: average high 68 °F, low 42 °F 68°42° OctNovember: average high 54 °F, low 30 °F 54°30° NovDecember: average high 42 °F, low 21 °F 42°21° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 1.02 in precipitation 1.0 JanFebruary: 1.42 in precipitation 1.4 FebMarch: 2.59 in precipitation 2.6 MarApril: 3.83 in precipitation 3.8 AprMay: 5.55 in precipitation 5.5 MayJune: 4.99 in precipitation 5.0 JunJuly: 4.72 in precipitation 4.7 JulAugust: 4.24 in precipitation 4.2 AugSeptember: 4.10 in precipitation 4.1 SepOctober: 3.16 in precipitation 3.2 OctNovember: 2.01 in precipitation 2.0 NovDecember: 1.51 in precipitation 1.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Leavenworth 3sw, KS (2 mi away); precipitation: Leavenworth 3sw, KS (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

660436b
Lansing, KS · 4 mi
660276b
Fort Leavenworth, KS · 7 mi
640286b
Farley, MO · 8 mi
660206b
Easton, KS · 8 mi
641686b
Kansas City, MO · 8 mi
641906b
Kansas City, MO · 8 mi
641956b
Kansas City, MO · 8 mi
660076b
Basehor, KS · 10 mi

Kansas planting zones →

Questions about 66048

What planting zone is ZIP code 66048?

ZIP code 66048 (Leavenworth, 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 Leavenworth, KS?

The median last spring frost (32 °F) near 66048 is April 19; after May 4 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Leavenworth 3sw station.

When is the first frost in Leavenworth, KS?

The median first fall frost near 66048 is October 19, giving a median frost-free growing season of 181 days.

When should I plant tomatoes in 66048?

Start tomato seeds indoors around Feb 22 – Mar 8 and set transplants outside around Apr 26 – May 10, one to three weeks after the median last frost.

How much rain and snow does 66048 get?

About 39.1 inches of precipitation a year (NOAA 1991–2020 normals, Leavenworth 3sw station).

How hot do summers get in Leavenworth, KS?

The average high peaks at 87 °F in July, with about 30 days a year at 90 °F or more.

What kind of soil does 66048 have?

The USDA soil survey maps Sharpsburg at the center of ZIP 66048: silty clay loam, moderately well drained, pH about 6.1 (slightly acidic).

Did spring come early in Leavenworth, KS in 2026?

Spring leaf-out near 66048 came on Feb 25 in 2026, 21 days earlier than the 1991–2020 average (Mar 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Leavenworth, KS?

Intermediate onions: the longest day near 66048 is 14 h 56 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 66048 change?

Yes. The 2012 USDA map put 66048 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.