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

Planting zone for 63365 — New Melle, MO

ZIP code 63365 (New Melle, Saint Charles County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 10 and the first fall frost October 26.

Where ZIP 63365 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 10

First frostOct 26

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 New Melle, 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 New Melle, MO

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 10median — 50% chance of a later frost

Safe for tender plantsApril 26only 10% chance of frost after

First fall frostOctober 26median — 10% chance by Oct 12

Growing season199 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 31 and returns around November 5.

From the NOAA station Weldon Spring NWS, MO — 11 miles away, elevation 610 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 63365

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 27 – Mar 13

SpinachSow outdoors · Feb 27 – Mar 20

Broccoli, cabbageStart indoors · Jan 30 – Feb 13

Broccoli, cabbageTransplant · Mar 20 – Apr 3

Onion setsPlant outdoors · Mar 13 – Mar 27

PotatoesPlant outdoors · Mar 20 – Apr 3

LettuceSow outdoors · Mar 13 – Mar 27

Carrots, beetsSow outdoors · Mar 20 – Apr 3

TomatoesStart indoors · Feb 13 – Feb 27

TomatoesTransplant · Apr 17 – May 1

Peppers, eggplantStart indoors · Jan 30 – Feb 13

Peppers, eggplantTransplant · Apr 24 – May 8

BeansSow outdoors · Apr 17 – May 1

Sweet cornSow outdoors · Apr 17 – May 1

Cucumbers, squashSow outdoors · Apr 17 – May 1

Fall lettuce, spinachSow outdoors · Aug 31 – Sep 14

GarlicPlant cloves · Oct 12 – Nov 16

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 10) and first fall frost (Oct 26) 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 63365 came on Mar 3 — 14 days earlier than the 1991–2020 average (Mar 17).

average
Mar 172026
Mar 3

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.

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 New Melle, MO.

Soil in New Melle, MO

The soil mapped at the center of ZIP 63365 is Mexico — silt loam, poorly drained.

TextureSilt loama good balance for most vegetables

pH6.5neutral; most vegetables like 6.0–7.0

DrainagePoorly drainedconsider raised beds

Organic matter1.87%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Mexico silt loam, 1 to 4 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 63365; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in New Melle, MO

Summer high88 °Faverage high, July

Winter low21 °Faverage low, January

Hot days36days a year at 90 °F or more

Freezing nights105nights a year at 32 °F or less

Growing degree days4,025base 50 °F — the season’s usable heat

Longest day14 h 53 mindaylight on June 21

Shortest day9 h 27 mindaylight on December 21

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

Precipitation44.4 inper year, rain and melted snow

Snowfall14 inper year; 15 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

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

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

633416b

Defiance, MO · 5 mi

633856b

Wentzville, MO · 6 mi

633676b

Lake Saint Louis, MO · 6 mi

Saint Charles, MO · 10 mi

Missouri planting zones →

Questions about 63365

What planting zone is ZIP code 63365?

ZIP code 63365 (New Melle, 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 New Melle, MO?

The median last spring frost (32 °F) near 63365 is April 10; after April 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Weldon Spring NWS station.

When is the first frost in New Melle, MO?

The median first fall frost near 63365 is October 26, giving a median frost-free growing season of 199 days.

When should I plant tomatoes in 63365?

Start tomato seeds indoors around Feb 13 – Feb 27 and set transplants outside around Apr 17 – May 1, one to three weeks after the median last frost.

How much rain and snow does 63365 get?

About 44.4 inches of precipitation a year and 14 inches of snowfall (NOAA 1991–2020 normals, Weldon Spring NWS station).

How hot do summers get in New Melle, MO?

The average high peaks at 88 °F in July, with about 36 days a year at 90 °F or more.

What kind of soil does 63365 have?

The USDA soil survey maps Mexico at the center of ZIP 63365: silt loam, poorly drained, pH about 6.5 (neutral).

Did spring come early in New Melle, MO in 2026?

Spring leaf-out near 63365 came on Mar 3 in 2026, 14 days earlier than the 1991–2020 average (Mar 17), according to the USA National Phenology Network Spring Index.

What kind of onions grow in New Melle, MO?

Intermediate onions: the longest day near 63365 is 14 h 53 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 63365 change?

Yes. The 2012 USDA map put 63365 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.