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

Planting zone for 64440 — De Kalb, MO

ZIP code 64440 (De Kalb, Buchanan County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 11 and the first fall frost October 29.

Where ZIP 64440 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 11
First frostOct 29
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 De Kalb, 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 De Kalb, MO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 11median — 50% chance of a later frost
Safe for tender plantsApril 23only 10% chance of frost after
First fall frostOctober 29median — 10% chance by Oct 15
Growing season199 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 1 and returns around November 5.

From the NOAA station Atchison, KS — 11 miles away, elevation 945 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 64440

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 28 – Mar 14
SpinachSow outdoors · Feb 28 – Mar 21
Broccoli, cabbageStart indoors · Jan 31 – Feb 14
Broccoli, cabbageTransplant · Mar 21 – Apr 4
Onion setsPlant outdoors · Mar 14 – Mar 28
PotatoesPlant outdoors · Mar 21 – Apr 4
LettuceSow outdoors · Mar 14 – Mar 28
Carrots, beetsSow outdoors · Mar 21 – Apr 4
TomatoesStart indoors · Feb 14 – Feb 28
TomatoesTransplant · Apr 18 – May 2
Peppers, eggplantStart indoors · Jan 31 – Feb 14
Peppers, eggplantTransplant · Apr 25 – May 9
BeansSow outdoors · Apr 18 – May 2
Sweet cornSow outdoors · Apr 18 – May 2
Cucumbers, squashSow outdoors · Apr 18 – May 2
Fall lettuce, spinachSow outdoors · Sep 3 – Sep 17
GarlicPlant cloves · Oct 15 – Nov 19
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 11) and first fall frost (Oct 29) 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 64440 came on Feb 28 — 20 days earlier than the 1991–2020 average (Mar 20).

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 6b in Missouri

525 plants native to the lower 48 states, recorded in Missouri, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. Each links to its USDA PLANTS profile.

Trees 70

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Fbald cypress130 ft · blooms mid spring · medium shade tolerance · to −18 °F

Shrubs 83

alternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican beautyberry6 ft · blooms early summer · medium shade tolerance · to −8 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °F

Wildflowers & perennials 192

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 157

alkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAmerican cupscale3 ft · blooms early summer · high shade tolerance · to −18 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBicknell's sedge3 ft · blooms late spring · low shade tolerance · to −38 °Fbig bluestem6 ft · blooms summer · high shade tolerance · to −46 °Fblister sedge3 ft · blooms late spring · medium shade tolerance · to −38 °F

Vines 12

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °Fheartleaf peppervine2 ft · blooms late spring · low shade tolerance · to −8 °F

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 De Kalb, MO.

Soil in De Kalb, MO

The soil mapped at the center of ZIP 64440 is Knox — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH6.5neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupBwater soaks in moderately
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Knox silt loam, 9 to 14 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 64440; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in De Kalb, MO

Summer high88 °Faverage high, July
Winter low18 °Faverage low, January
Hot days38days a year at 90 °F or more
Freezing nights107nights a year at 32 °F or less
Growing degree days4,006base 50 °F — the season’s usable heat
Longest day14 h 58 mindaylight on June 21
Shortest day9 h 22 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation36.4 inper year, rain and melted snow
Snowfall17 inper year; 23 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 36 °F, low 18 °F 36°18° JanFebruary: average high 42 °F, low 23 °F 42°23° FebMarch: average high 54 °F, low 32 °F 54°32° MarApril: average high 65 °F, low 43 °F 65°43° AprMay: average high 74 °F, low 55 °F 74°55° MayJune: average high 84 °F, low 65 °F 84°65° JunJuly: average high 88 °F, low 69 °F 88°69° JulAugust: average high 86 °F, low 67 °F 86°67° AugSeptember: average high 79 °F, low 58 °F 79°58° SepOctober: average high 67 °F, low 46 °F 67°46° OctNovember: average high 52 °F, low 33 °F 52°33° NovDecember: average high 40 °F, low 23 °F 40°23° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 0.93 in precipitation, 5 in snowfall 0.9❄5 JanFebruary: 1.20 in precipitation, 4.8 in snowfall 1.2❄5 FebMarch: 1.92 in precipitation, 1.8 in snowfall 1.9❄2 MarApril: 3.42 in precipitation, 0.4 in snowfall 3.4 AprMay: 5.32 in precipitation 5.3 MayJune: 4.87 in precipitation 4.9 JunJuly: 5.17 in precipitation 5.2 JulAugust: 3.75 in precipitation 3.8 AugSeptember: 3.48 in precipitation 3.5 SepOctober: 3.10 in precipitation, 0.3 in snowfall 3.1 OctNovember: 1.81 in precipitation, 0.9 in snowfall 1.8❄1 NovDecember: 1.41 in precipitation, 3.8 in snowfall 1.4❄4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Atchison, KS (11 mi away); precipitation: Atchison, KS (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

644486a
Faucett, MO · 5 mi
644846a
Rushville, MO · 6 mi
645086a
Saint Joseph, MO · 7 mi
645046a
Saint Joseph, MO · 7 mi
640986a
Weston, MO · 8 mi
644396a
Dearborn, MO · 9 mi
644016a
Agency, MO · 11 mi
645036a
Saint Joseph, MO · 12 mi

Missouri planting zones →

Questions about 64440

What planting zone is ZIP code 64440?

ZIP code 64440 (De Kalb, MO) 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 De Kalb, MO?

The median last spring frost (32 °F) near 64440 is April 11; after April 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Atchison station.

When is the first frost in De Kalb, MO?

The median first fall frost near 64440 is October 29, giving a median frost-free growing season of 199 days.

When should I plant tomatoes in 64440?

Start tomato seeds indoors around Feb 14 – Feb 28 and set transplants outside around Apr 18 – May 2, one to three weeks after the median last frost.

How much rain and snow does 64440 get?

About 36.4 inches of precipitation a year and 17 inches of snowfall (NOAA 1991–2020 normals, Atchison station).

How hot do summers get in De Kalb, MO?

The average high peaks at 88 °F in July, with about 38 days a year at 90 °F or more.

What kind of soil does 64440 have?

The USDA soil survey maps Knox at the center of ZIP 64440: silt loam, well drained, pH about 6.5 (neutral).

Did spring come early in De Kalb, MO in 2026?

Spring leaf-out near 64440 came on Feb 28 in 2026, 20 days earlier than the 1991–2020 average (Mar 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in De Kalb, MO?

Intermediate onions: the longest day near 64440 is 14 h 58 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 64440 change?

Yes. The 2012 USDA map put 64440 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.