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

Planting zone for 64436 — Cosby, MO

ZIP code 64436 (Cosby, Andrew County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 17 and the first fall frost October 19.

Where ZIP 64436 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 17

First frostOct 19

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 Cosby, MO…

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 Cosby, MO

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 17median — 50% chance of a later frost

Safe for tender plantsMay 1only 10% chance of frost after

First fall frostOctober 19median — 10% chance by Oct 4

Growing season184 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 7 and returns around October 28.

From the NOAA station Cosby 2w, MO — within 1 mile, elevation 909 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 64436

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 6 – Mar 20

SpinachSow outdoors · Mar 6 – Mar 27

Broccoli, cabbageStart indoors · Feb 6 – Feb 20

Broccoli, cabbageTransplant · Mar 27 – Apr 10

Onion setsPlant outdoors · Mar 20 – Apr 3

PotatoesPlant outdoors · Mar 27 – Apr 10

LettuceSow outdoors · Mar 20 – Apr 3

Carrots, beetsSow outdoors · Mar 27 – Apr 10

TomatoesStart indoors · Feb 20 – Mar 6

TomatoesTransplant · Apr 24 – May 8

Peppers, eggplantStart indoors · Feb 6 – Feb 20

Peppers, eggplantTransplant · May 1 – May 15

BeansSow outdoors · Apr 24 – May 8

Sweet cornSow outdoors · Apr 24 – May 8

Cucumbers, squashSow outdoors · Apr 24 – May 8

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 17) 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 64436 came on Mar 10 — 13 days earlier than the 1991–2020 average (Mar 23).

average
Mar 232026
Mar 10

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 Missouri

516 plants native to the lower 48 states, recorded in Missouri, 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 Cosby, MO.

Soil in Cosby, MO

The soil mapped at the center of ZIP 64436 is Zook — silty clay loam, poorly drained.

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

pH6.1slightly acidic; most vegetables like 6.0–7.0

DrainagePoorly drainedconsider raised beds

Organic matter6%high

Hydrologic groupDwater soaks in very slowly

Farmland classPrime farmland if drainedUSDA classification

Map unit: Zook silty clay loam, heavy till, 0 to 2 percent slopes, occasionally flooded.

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 64436; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Cosby, MO

Summer high87 °Faverage high, July

Winter low16 °Faverage low, January

Hot days33days a year at 90 °F or more

Freezing nights130nights a year at 32 °F or less

Growing degree days3,638base 50 °F — the season’s usable heat

Longest day15 h 00 mindaylight on June 21

Shortest day9 h 20 mindaylight on December 21

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

Precipitation37.1 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cosby 2w, MO (within 1 mile); precipitation: Cosby 2w, MO (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

644596a

Helena, MO · 6 mi

644306a

Clarksdale, MO · 7 mi

645056a

Saint Joseph, MO · 7 mi

645066a

Saint Joseph, MO · 7 mi

644436a

Easton, MO · 8 mi

645076a

Saint Joseph, MO · 8 mi

644856a

Savannah, MO · 10 mi

645026a

Saint Joseph, MO · 10 mi

Missouri planting zones →

Questions about 64436

What planting zone is ZIP code 64436?

ZIP code 64436 (Cosby, MO) 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 Cosby, MO?

The median last spring frost (32 °F) near 64436 is April 17; after May 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cosby 2w station.

When is the first frost in Cosby, MO?

The median first fall frost near 64436 is October 19, giving a median frost-free growing season of 184 days.

When should I plant tomatoes in 64436?

Start tomato seeds indoors around Feb 20 – Mar 6 and set transplants outside around Apr 24 – May 8, one to three weeks after the median last frost.

How much rain and snow does 64436 get?

About 37.1 inches of precipitation a year (NOAA 1991–2020 normals, Cosby 2w station).

How hot do summers get in Cosby, MO?

The average high peaks at 87 °F in July, with about 33 days a year at 90 °F or more.

What kind of soil does 64436 have?

The USDA soil survey maps Zook at the center of ZIP 64436: silty clay loam, poorly drained, pH about 6.1 (slightly acidic).

Did spring come early in Cosby, MO in 2026?

Spring leaf-out near 64436 came on Mar 10 in 2026, 13 days earlier than the 1991–2020 average (Mar 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Cosby, MO?

Intermediate onions: the longest day near 64436 is 15 h 00 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 64436 change?

Yes. The 2012 USDA map put 64436 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.