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

Planting zone for 64446 — Fairfax, MO

ZIP code 64446 (Fairfax, Atchison County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 19 and the first fall frost October 15.

Where ZIP 64446 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.

Zone5b−15 to −10 °F
Coldest night−26.1 to −23.3 °C
Last frostApr 19
First frostOct 15
2012 zone5b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Fairfax, 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 Fairfax, 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 4only 10% chance of frost after
First fall frostOctober 15median — 10% chance by Oct 1
Growing season177 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 9 and returns around October 25.

From the NOAA station Tarkio, MO — 7 miles away, elevation 1,047 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 64446

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 20 – Sep 3
GarlicPlant cloves · Oct 1 – Nov 5
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Oct 15) 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 64446 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 5b in Missouri

491 plants native to the lower 48 states, recorded in Missouri, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.

Trees 66

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 78

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 181

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 149

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 8

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °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 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °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 Fairfax, MO.

Soil in Fairfax, MO

The soil mapped at the center of ZIP 64446 is Colo — silty clay loam, poorly drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH6.3slightly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter6%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Colo silt loam, deep loess, 0 to 2 percent slopes, occasionally flooded.

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 64446; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Fairfax, MO

Summer high85 °Faverage high, July
Winter low15 °Faverage low, January
Hot days26days a year at 90 °F or more
Freezing nights138nights a year at 32 °F or less
Growing degree days3,402base 50 °F — the season’s usable heat
Longest day15 h 03 mindaylight on June 21
Shortest day9 h 17 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation34.7 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 33 °F, low 15 °F 33°15° JanFebruary: average high 38 °F, low 18 °F 38°18° FebMarch: average high 52 °F, low 29 °F 52°29° MarApril: average high 63 °F, low 39 °F 63°39° AprMay: average high 72 °F, low 51 °F 72°51° 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 63 °F 84°63° AugSeptember: average high 78 °F, low 54 °F 78°54° SepOctober: average high 65 °F, low 40 °F 65°40° OctNovember: average high 50 °F, low 30 °F 50°30° NovDecember: average high 37 °F, low 20 °F 37°20° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 0.74 in precipitation 0.7 JanFebruary: 1.26 in precipitation 1.3 FebMarch: 2.21 in precipitation 2.2 MarApril: 3.42 in precipitation 3.4 AprMay: 4.97 in precipitation 5.0 MayJune: 4.67 in precipitation 4.7 JunJuly: 5.16 in precipitation 5.2 JulAugust: 3.88 in precipitation 3.9 AugSeptember: 2.61 in precipitation 2.6 SepOctober: 2.77 in precipitation 2.8 OctNovember: 1.66 in precipitation 1.7 NovDecember: 1.31 in precipitation 1.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Tarkio, MO (7 mi away); precipitation: Rockport 0.5 E, MO (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

644915b
Tarkio, MO · 9 mi
644825b
Rock Port, MO · 12 mi
644376a
Craig, MO · 13 mi
684376a
Shubert, NE · 14 mi
644706a
Mound City, MO · 14 mi
644985b
Westboro, MO · 16 mi
684145b
Nemaha, NE · 16 mi
644875b
Skidmore, MO · 16 mi

Missouri planting zones →

Questions about 64446

What planting zone is ZIP code 64446?

ZIP code 64446 (Fairfax, MO) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Fairfax, MO?

The median last spring frost (32 °F) near 64446 is April 19; after May 4 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Tarkio station.

When is the first frost in Fairfax, MO?

The median first fall frost near 64446 is October 15, giving a median frost-free growing season of 177 days.

When should I plant tomatoes in 64446?

Start tomato seeds indoors around Feb 22 – Mar 8 and set transplants outside around Apr 26 – May 10, one to three weeks after the median last frost.

How much rain and snow does 64446 get?

About 34.7 inches of precipitation a year (NOAA 1991–2020 normals, Rockport 0.5 E station).

How hot do summers get in Fairfax, MO?

The average high peaks at 85 °F in July, with about 26 days a year at 90 °F or more.

What kind of soil does 64446 have?

The USDA soil survey maps Colo at the center of ZIP 64446: silty clay loam, poorly drained, pH about 6.3 (slightly acidic).

Did spring come early in Fairfax, MO in 2026?

Spring leaf-out near 64446 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 Fairfax, MO?

Long-day onions: the longest day near 64446 is 15 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).