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

Planting zone for 63557 — New Boston, MO

ZIP code 63557 (New Boston, Linn 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 20.

Where ZIP 63557 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 20
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 New Boston, 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 Boston, 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 plantsMay 2only 10% chance of frost after
First fall frostOctober 20median — 10% chance by Oct 5
Growing season184 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around October 29.

From the NOAA station Chillicothe 22 Ene, MO — 16 miles away, elevation 833 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 63557

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 25 – Sep 8
GarlicPlant cloves · Oct 6 – Nov 10
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 15) and first fall frost (Oct 20) 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 63557 came on Mar 10 — 17 days earlier than the 1991–2020 average (Mar 27).

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.

Trees 68

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 82

alternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °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 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °F

Wildflowers & perennials 190

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 155

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 10

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 °Fmuscadine30 ft · blooms late spring · medium shade tolerance · to −18 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °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 New Boston, MO.

Soil in New Boston, MO

The soil mapped at the center of ZIP 63557 is Armstrong — clay loam, somewhat poorly drained.

TextureClay loamholds water and nutrients; slow to drain and warm up
pH6.5neutral; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter1.5%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Armstrong clay loam, 5 to 9 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 63557; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in New Boston, MO

Summer high85 °Faverage high, July
Winter low18 °Faverage low, January
Hot days22days a year at 90 °F or more
Freezing nights116nights a year at 32 °F or less
Growing degree days3,545base 50 °F — the season’s usable heat
Longest day15 h 01 mindaylight on June 21
Shortest day9 h 20 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation40 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 35 °F, low 18 °F 35°18° JanFebruary: average high 40 °F, low 22 °F 40°22° FebMarch: average high 53 °F, low 32 °F 53°32° MarApril: average high 64 °F, low 42 °F 64°42° AprMay: average high 73 °F, low 53 °F 73°53° MayJune: average high 82 °F, low 62 °F 82°62° JunJuly: average high 85 °F, low 66 °F 85°66° JulAugust: average high 84 °F, low 64 °F 84°64° AugSeptember: average high 77 °F, low 55 °F 77°55° SepOctober: average high 65 °F, low 44 °F 65°44° OctNovember: average high 51 °F, low 32 °F 51°32° NovDecember: average high 39 °F, low 23 °F 39°23° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 1.35 in precipitation 1.4 JanFebruary: 1.72 in precipitation 1.7 FebMarch: 2.72 in precipitation 2.7 MarApril: 3.65 in precipitation 3.6 AprMay: 5.36 in precipitation 5.4 MayJune: 5.22 in precipitation 5.2 JunJuly: 4.78 in precipitation 4.8 JulAugust: 3.78 in precipitation 3.8 AugSeptember: 4.27 in precipitation 4.3 SepOctober: 3.26 in precipitation 3.3 OctNovember: 2.31 in precipitation 2.3 NovDecember: 1.56 in precipitation 1.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Chillicothe 22 Ene, MO (16 mi away); precipitation: Brookfield 3.7 Nne, MO (14 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

635666a
Winigan, MO · 5 mi
635396a
Ethel, MO · 7 mi
646316a
Bucklin, MO · 10 mi
635386a
Elmer, MO · 11 mi
646746a
Purdin, MO · 15 mi
646306a
Browning, MO · 15 mi
646286a
Brookfield, MO · 16 mi
635586a
New Cambria, MO · 18 mi

Missouri planting zones →

Questions about 63557

What planting zone is ZIP code 63557?

ZIP code 63557 (New Boston, 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 New Boston, MO?

The median last spring frost (32 °F) near 63557 is April 15; after May 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Chillicothe 22 Ene station.

When is the first frost in New Boston, MO?

The median first fall frost near 63557 is October 20, giving a median frost-free growing season of 184 days.

When should I plant tomatoes in 63557?

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 63557 get?

About 40 inches of precipitation a year (NOAA 1991–2020 normals, Brookfield 3.7 Nne station).

How hot do summers get in New Boston, MO?

The average high peaks at 85 °F in July, with about 22 days a year at 90 °F or more.

What kind of soil does 63557 have?

The USDA soil survey maps Armstrong at the center of ZIP 63557: clay loam, somewhat poorly drained, pH about 6.5 (neutral).

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

Spring leaf-out near 63557 came on Mar 10 in 2026, 17 days earlier than the 1991–2020 average (Mar 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in New Boston, MO?

Long-day onions: the longest day near 63557 is 15 h 01 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 63557 change?

Yes. The 2012 USDA map put 63557 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.