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

Planting zone for 64474 — Osborn, MO

ZIP code 64474 (Osborn, DeKalb County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 15 and the first fall frost October 24.

Where ZIP 64474 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 15

First frostOct 24

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 Osborn, 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 Osborn, MO

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 29only 10% chance of frost after

First fall frostOctober 24median — 10% chance by Oct 10

Growing season192 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around November 3.

From the NOAA station Cameron, MO — 7 miles away, elevation 1,011 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 64474

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 29 – Sep 12

GarlicPlant cloves · Oct 10 – Nov 14

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 15) and first fall frost (Oct 24) 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 64474 came on Mar 8 — 16 days earlier than the 1991–2020 average (Mar 24).

average
Mar 242026
Mar 8

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 Osborn, MO

The soil mapped at the center of ZIP 64474 is Grundy — silty clay loam, somewhat poorly drained.

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

pH6.0slightly acidic; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter3%moderate

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classPrime farmland if drainedUSDA classification

Map unit: Grundy silty clay loam, 2 to 5 percent slopes, moderately 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 64474; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Osborn, MO

Summer high87 °Faverage high, July

Winter low15 °Faverage low, January

Hot days35days a year at 90 °F or more

Freezing nights132nights a year at 32 °F or less

Growing degree days3,646base 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

Precipitation38 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: Cameron, MO (7 mi away); precipitation: Stewartsville 2.8 Nne, MO (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

644906a

Stewartsville, MO · 7 mi

Clarksdale, MO · 11 mi

644696a

Maysville, MO · 12 mi

644776a

Plattsburg, MO · 13 mi

644436a

Easton, MO · 15 mi

Missouri planting zones →

Questions about 64474

What planting zone is ZIP code 64474?

ZIP code 64474 (Osborn, 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 Osborn, MO?

The median last spring frost (32 °F) near 64474 is April 15; after April 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cameron station.

When is the first frost in Osborn, MO?

The median first fall frost near 64474 is October 24, giving a median frost-free growing season of 192 days.

When should I plant tomatoes in 64474?

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 64474 get?

About 38 inches of precipitation a year (NOAA 1991–2020 normals, Stewartsville 2.8 Nne station).

How hot do summers get in Osborn, MO?

The average high peaks at 87 °F in July, with about 35 days a year at 90 °F or more.

What kind of soil does 64474 have?

The USDA soil survey maps Grundy at the center of ZIP 64474: silty clay loam, somewhat poorly drained, pH about 6.0 (slightly acidic).

Did spring come early in Osborn, MO in 2026?

Spring leaf-out near 64474 came on Mar 8 in 2026, 16 days earlier than the 1991–2020 average (Mar 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Osborn, MO?

Intermediate onions: the longest day near 64474 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 64474 change?

Yes. The 2012 USDA map put 64474 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.