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

Planting zone for Saint Joseph, MO

Saint Joseph, MO is in USDA zone 6a across its 8 ZIP codes. The median last spring frost is April 19 and the first fall frost October 17.

Saint Joseph on the zone map

Outlined: its 6 ZIP code areas · 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
ZIP codes8
Last frostApr 19
First frostOct 17
Growing season180 days

6a 8 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 Saint Joseph, MO

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 19median — 50% chance of a later frost
Safe for tender plantsMay 3only 10% chance of frost after
First fall frostOctober 17median — 10% chance by Sep 30
Growing season180 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 9 and returns around October 26.

From the NOAA station St Joseph Rosecrans Airport, MO, elevation 817 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 Saint Joseph

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 8 – Mar 22
SpinachSow outdoors · Mar 8 – Mar 29
Broccoli, cabbageStart indoors · Feb 8 – Feb 22
Broccoli, cabbageTransplant · Mar 29 – Apr 12
Onion setsPlant outdoors · Mar 22 – Apr 5
PotatoesPlant outdoors · Mar 29 – Apr 12
LettuceSow outdoors · Mar 22 – Apr 5
Carrots, beetsSow outdoors · Mar 29 – Apr 12
TomatoesStart indoors · Feb 22 – Mar 8
TomatoesTransplant · Apr 26 – May 10
Peppers, eggplantStart indoors · Feb 8 – Feb 22
Peppers, eggplantTransplant · May 3 – May 17
BeansSow outdoors · Apr 26 – May 10
Sweet cornSow outdoors · Apr 26 – May 10
Cucumbers, squashSow outdoors · Apr 26 – May 10
Fall lettuce, spinachSow outdoors · Aug 22 – Sep 5
GarlicPlant cloves · Oct 3 – Nov 7
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Oct 17) 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 64503 came on Mar 7 — 15 days earlier than the 1991–2020 average (Mar 22).

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 Saint Joseph, MO.

Soil in Saint Joseph, MO

The center of ZIP 64503 is mapped as Urban land, bottomland, 0 to 3 percent slopes, rarely flooded: built-over ground without natural soil data. Garden soil here is usually imported or disturbed — test before you plant.

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 64503; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Saint Joseph, MO

Summer high88 °Faverage high, July
Winter low17 °Faverage low, January
Hot days39days a year at 90 °F or more
Freezing nights126nights a year at 32 °F or less
Growing degree days3,861base 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
Precipitation37 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 37 °F, low 17 °F 37°17° JanFebruary: average high 43 °F, low 21 °F 43°21° FebMarch: average high 55 °F, low 32 °F 55°32° MarApril: average high 66 °F, low 42 °F 66°42° AprMay: average high 76 °F, low 54 °F 76°54° MayJune: average high 85 °F, low 64 °F 85°64° JunJuly: average high 88 °F, low 67 °F 88°67° JulAugust: average high 86 °F, low 65 °F 86°65° AugSeptember: average high 80 °F, low 54 °F 80°54° SepOctober: average high 68 °F, low 43 °F 68°43° OctNovember: average high 53 °F, low 31 °F 53°31° NovDecember: average high 41 °F, low 21 °F 41°21° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 0.97 in precipitation 1.0 JanFebruary: 1.23 in precipitation 1.2 FebMarch: 2.33 in precipitation 2.3 MarApril: 3.59 in precipitation 3.6 AprMay: 4.96 in precipitation 5.0 MayJune: 4.76 in precipitation 4.8 JunJuly: 5.04 in precipitation 5.0 JulAugust: 3.94 in precipitation 3.9 AugSeptember: 3.54 in precipitation 3.5 SepOctober: 3.13 in precipitation 3.1 OctNovember: 2.02 in precipitation 2.0 NovDecember: 1.48 in precipitation 1.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: St Joseph Rosecrans Airport, MO (4 mi away); precipitation: St Joseph Roserans Ang, MO (3 mi away). Daylight is calculated from latitude.

ZIP codes in Saint Joseph

645016a
−10 to −5 °F
645026a
−10 to −5 °F
645036a
−10 to −5 °F
645046a
−10 to −5 °F
645056a
−10 to −5 °F
645066a
−10 to −5 °F
645076a
−10 to −5 °F
645086a
−10 to −5 °F

Missouri planting zones →

Questions about Saint Joseph

What planting zone is Saint Joseph, MO?

Saint Joseph, MO is in USDA hardiness zone 6a on the 2023 map (6a: −10 to −5 °F).

When is the last frost in Saint Joseph, MO?

The median last spring frost is April 19 and the median first fall frost is October 17 (NOAA 1991–2020 normals, St Joseph Rosecrans Airport station).

When can I plant a garden in Saint Joseph, MO?

Cool-season crops like peas and spinach go in around Mar 8 – Mar 29; tomatoes, peppers, beans and squash after about Apr 26, once frost risk has passed.

What kind of onions grow in Saint Joseph, MO?

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

How much rain and snow does Saint Joseph, MO get?

About 37 inches of precipitation a year (NOAA 1991–2020 normals).