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

Planting zone for 50435 — Floyd, IA

ZIP code 50435 (Floyd, Floyd County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 30 and the first fall frost October 6.

Where ZIP 50435 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostApr 30
First frostOct 6
2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Floyd, IA…

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 Floyd, IA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 30median — 50% chance of a later frost
Safe for tender plantsMay 14only 10% chance of frost after
First fall frostOctober 6median — 10% chance by Sep 21
Growing season157 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 21 and returns around October 17.

From the NOAA station Charles City, IA — 8 miles away, elevation 994 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 50435

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 19 – Apr 2
SpinachSow outdoors · Mar 19 – Apr 9
Broccoli, cabbageStart indoors · Feb 19 – Mar 5
Broccoli, cabbageTransplant · Apr 9 – Apr 23
Onion setsPlant outdoors · Apr 2 – Apr 16
PotatoesPlant outdoors · Apr 9 – Apr 23
LettuceSow outdoors · Apr 2 – Apr 16
Carrots, beetsSow outdoors · Apr 9 – Apr 23
TomatoesStart indoors · Mar 5 – Mar 19
TomatoesTransplant · May 7 – May 21
Peppers, eggplantStart indoors · Feb 19 – Mar 5
Peppers, eggplantTransplant · May 14 – May 28
BeansSow outdoors · May 7 – May 21
Sweet cornSow outdoors · May 7 – May 21
Cucumbers, squashSow outdoors · May 7 – May 21
Fall lettuce, spinachSow outdoors · Aug 11 – Aug 25
GarlicPlant cloves · Sep 22 – Oct 27
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 6) 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 50435 came on Mar 30 — 14 days earlier than the 1991–2020 average (Apr 13).

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 5a in Iowa

461 plants native to the lower 48 states, recorded in Iowa, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 46

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °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 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °Fbalsam fir60 ft · blooms mid summer · low shade tolerance · to −43 °F

Shrubs 77

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf 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 hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °F

Wildflowers & perennials 185

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 133

arctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBebb's sedge3 ft · blooms late 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 °Fblue grama1 ft · blooms early summer · high shade tolerance · to −43 °F

Vines 7

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 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °Ftrumpet honeysuckle16 ft · blooms late summer · low 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 Floyd, IA.

Soil in Floyd, IA

The soil mapped at the center of ZIP 50435 is Ostrander — loam, well drained.

TextureLoama good balance for most vegetables
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3.5%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Ostrander loam, 2 to 5 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 50435; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Floyd, IA

Summer high82 °Faverage high, July
Winter low9 °Faverage low, January
Hot days9days a year at 90 °F or more
Freezing nights154nights a year at 32 °F or less
Growing degree days2,754base 50 °F — the season’s usable heat
Longest day15 h 23 mindaylight on June 21
Shortest day8 h 59 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation37.7 inper year, rain and melted snow
Snowfall38 inper year; 81 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 25 °F, low 9 °F 25°9° JanFebruary: average high 30 °F, low 13 °F 30°13° FebMarch: average high 43 °F, low 25 °F 43°25° MarApril: average high 58 °F, low 37 °F 58°37° AprMay: average high 70 °F, low 49 °F 70°49° MayJune: average high 79 °F, low 59 °F 79°59° JunJuly: average high 82 °F, low 62 °F 82°62° JulAugust: average high 80 °F, low 60 °F 80°60° AugSeptember: average high 73 °F, low 51 °F 73°51° SepOctober: average high 60 °F, low 39 °F 60°39° OctNovember: average high 44 °F, low 26 °F 44°26° NovDecember: average high 30 °F, low 15 °F 30°15° Dec

Precipitation by month inches · ❄ = snowfall

0″2″4″6″January: 1.01 in precipitation, 9.5 in snowfall 1.0❄10 JanFebruary: 1.14 in precipitation, 9.3 in snowfall 1.1❄9 FebMarch: 1.93 in precipitation, 5.4 in snowfall 1.9❄5 MarApril: 3.73 in precipitation, 2.1 in snowfall 3.7❄2 AprMay: 5.06 in precipitation, 0.3 in snowfall 5.1 MayJune: 6.13 in precipitation 6.1 JunJuly: 4.92 in precipitation 4.9 JulAugust: 4.28 in precipitation 4.3 AugSeptember: 3.82 in precipitation 3.8 SepOctober: 2.58 in precipitation, 0.1 in snowfall 2.6 OctNovember: 1.74 in precipitation, 2.8 in snowfall 1.7❄3 NovDecember: 1.38 in precipitation, 8 in snowfall 1.4❄8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Charles City, IA (8 mi away); precipitation: Charles City, IA (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

504715a
Rudd, IA · 6 mi
504605a
Orchard, IA · 6 mi
506165a
Charles City, IA · 8 mi
506205a
Colwell, IA · 9 mi
504615a
Osage, IA · 11 mi
504585a
Nora Springs, IA · 12 mi
504685a
Rockford, IA · 12 mi
506535a
Marble Rock, IA · 14 mi

Iowa planting zones →

Questions about 50435

What planting zone is ZIP code 50435?

ZIP code 50435 (Floyd, IA) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Floyd, IA?

The median last spring frost (32 °F) near 50435 is April 30; after May 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Charles City station.

When is the first frost in Floyd, IA?

The median first fall frost near 50435 is October 6, giving a median frost-free growing season of 157 days.

When should I plant tomatoes in 50435?

Start tomato seeds indoors around Mar 5 – Mar 19 and set transplants outside around May 7 – May 21, one to three weeks after the median last frost.

How much rain and snow does 50435 get?

About 37.7 inches of precipitation a year and 38 inches of snowfall (NOAA 1991–2020 normals, Charles City station).

How hot do summers get in Floyd, IA?

The average high peaks at 82 °F in July, with about 9 days a year at 90 °F or more.

What kind of soil does 50435 have?

The USDA soil survey maps Ostrander at the center of ZIP 50435: loam, well drained, pH about 6.2 (slightly acidic).

Did spring come early in Floyd, IA in 2026?

Spring leaf-out near 50435 came on Mar 30 in 2026, 14 days earlier than the 1991–2020 average (Apr 13), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Floyd, IA?

Long-day onions: the longest day near 50435 is 15 h 23 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).