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

Planting zone for 64840 — Diamond, MO

ZIP code 64840 (Diamond, Newton County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 18 and the first fall frost October 22.

Where ZIP 64840 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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostApr 18
First frostOct 22
2012 zone6b

Was 6b 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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Diamond, 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 Diamond, MO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 18median — 50% chance of a later frost
Safe for tender plantsMay 3only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 7
Growing season184 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 6 and returns around October 30.

From the NOAA station Diamond 2w, MO — 2 miles away, elevation 1,070 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 64840

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 7 – Mar 21
SpinachSow outdoors · Mar 7 – Mar 28
Broccoli, cabbageStart indoors · Feb 7 – Feb 21
Broccoli, cabbageTransplant · Mar 28 – Apr 11
Onion setsPlant outdoors · Mar 21 – Apr 4
PotatoesPlant outdoors · Mar 28 – Apr 11
LettuceSow outdoors · Mar 21 – Apr 4
Carrots, beetsSow outdoors · Mar 28 – Apr 11
TomatoesStart indoors · Feb 21 – Mar 7
TomatoesTransplant · Apr 25 – May 9
Peppers, eggplantStart indoors · Feb 7 – Feb 21
Peppers, eggplantTransplant · May 2 – May 16
BeansSow outdoors · Apr 25 – May 9
Sweet cornSow outdoors · Apr 25 – May 9
Cucumbers, squashSow outdoors · Apr 25 – May 9
Fall lettuce, spinachSow outdoors · Aug 27 – Sep 10
GarlicPlant cloves · Oct 8 – Nov 12
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Oct 22) 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 64840 came on Feb 17 — 17 days earlier than the 1991–2020 average (Mar 6).

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 Diamond, MO

The soil mapped at the center of ZIP 64840 is Gerald — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH5.9moderately acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter1.7%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Gerald silt loam, 0 to 2 percent slopes.

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 64840; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Diamond, MO

Summer high90 °Faverage high, July
Winter low23 °Faverage low, January
Hot days46days a year at 90 °F or more
Freezing nights104nights a year at 32 °F or less
Growing degree days4,262base 50 °F — the season’s usable heat
Longest day14 h 42 mindaylight on June 21
Shortest day9 h 37 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation46.9 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 46 °F, low 23 °F 46°23° JanFebruary: average high 51 °F, low 26 °F 51°26° FebMarch: average high 60 °F, low 35 °F 60°35° MarApril: average high 69 °F, low 44 °F 69°44° AprMay: average high 76 °F, low 54 °F 76°54° MayJune: average high 85 °F, low 63 °F 85°63° JunJuly: average high 90 °F, low 67 °F 90°67° JulAugust: average high 90 °F, low 65 °F 90°65° AugSeptember: average high 83 °F, low 57 °F 83°57° SepOctober: average high 72 °F, low 45 °F 72°45° OctNovember: average high 59 °F, low 35 °F 59°35° NovDecember: average high 49 °F, low 26 °F 49°26° Dec

Precipitation by month inches

0″2″4″6″January: 1.91 in precipitation 1.9 JanFebruary: 2.24 in precipitation 2.2 FebMarch: 3.54 in precipitation 3.5 MarApril: 5.24 in precipitation 5.2 AprMay: 6.71 in precipitation 6.7 MayJune: 5.49 in precipitation 5.5 JunJuly: 3.80 in precipitation 3.8 JulAugust: 3.48 in precipitation 3.5 AugSeptember: 4.48 in precipitation 4.5 SepOctober: 3.89 in precipitation 3.9 OctNovember: 3.58 in precipitation 3.6 NovDecember: 2.51 in precipitation 2.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Diamond 2w, MO (2 mi away); precipitation: Diamond 2w, MO (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

648417a
Duenweg, MO · 6 mi
648647a
Saginaw, MO · 7 mi
648047a
Joplin, MO · 9 mi
648447a
Granby, MO · 9 mi
648357a
Carterville, MO · 10 mi
648027a
Joplin, MO · 10 mi
648037a
Joplin, MO · 10 mi
648017a
Joplin, MO · 10 mi

Missouri planting zones →

Questions about 64840

What planting zone is ZIP code 64840?

ZIP code 64840 (Diamond, MO) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Diamond, MO?

The median last spring frost (32 °F) near 64840 is April 18; after May 3 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Diamond 2w station.

When is the first frost in Diamond, MO?

The median first fall frost near 64840 is October 22, giving a median frost-free growing season of 184 days.

When should I plant tomatoes in 64840?

Start tomato seeds indoors around Feb 21 – Mar 7 and set transplants outside around Apr 25 – May 9, one to three weeks after the median last frost.

How much rain and snow does 64840 get?

About 46.9 inches of precipitation a year (NOAA 1991–2020 normals, Diamond 2w station).

How hot do summers get in Diamond, MO?

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

What kind of soil does 64840 have?

The USDA soil survey maps Gerald at the center of ZIP 64840: silt loam, somewhat poorly drained, pH about 5.9 (moderately acidic).

Did spring come early in Diamond, MO in 2026?

Spring leaf-out near 64840 came on Feb 17 in 2026, 17 days earlier than the 1991–2020 average (Mar 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Diamond, MO?

Intermediate onions: the longest day near 64840 is 14 h 42 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 64840 change?

Yes. The 2012 USDA map put 64840 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.