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

Planting zone for 50606 — Arlington, IA

ZIP code 50606 (Arlington, Fayette County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is April 27 and the first fall frost October 13.

Where ZIP 50606 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.

Zone4b−25 to −20 °F
Coldest night−31.7 to −28.9 °C
Last frostApr 27
First frostOct 13
2012 zone4b

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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Arlington, 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 Arlington, IA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 27median — 50% chance of a later frost
Safe for tender plantsMay 10only 10% chance of frost after
First fall frostOctober 13median — 10% chance by Sep 30
Growing season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 15 and returns around October 22.

From the NOAA station Oelwein 1e, IA — 11 miles away, elevation 1,165 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 50606

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 16 – Mar 30
SpinachSow outdoors · Mar 16 – Apr 6
Broccoli, cabbageStart indoors · Feb 16 – Mar 2
Broccoli, cabbageTransplant · Apr 6 – Apr 20
Onion setsPlant outdoors · Mar 30 – Apr 13
PotatoesPlant outdoors · Apr 6 – Apr 20
LettuceSow outdoors · Mar 30 – Apr 13
Carrots, beetsSow outdoors · Apr 6 – Apr 20
TomatoesStart indoors · Mar 2 – Mar 16
TomatoesTransplant · May 4 – May 18
Peppers, eggplantStart indoors · Feb 16 – Mar 2
Peppers, eggplantTransplant · May 11 – May 25
BeansSow outdoors · May 4 – May 18
Sweet cornSow outdoors · May 4 – May 18
Cucumbers, squashSow outdoors · May 4 – May 18
Fall lettuce, spinachSow outdoors · Aug 18 – Sep 1
GarlicPlant cloves · Sep 29 – Nov 3
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 27) and first fall frost (Oct 13) 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 50606 came on Mar 28 — 16 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 4b in Iowa

426 plants native to the lower 48 states, recorded in Iowa, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. Each links to its USDA PLANTS profile.

Trees 43

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 72

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 169

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 124

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 5

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Ftrumpet honeysuckle16 ft · blooms late summer · low shade tolerance · to −33 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °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 Arlington, IA.

Soil in Arlington, IA

The soil mapped at the center of ZIP 50606 is Bassett — loam, moderately well drained.

TextureLoama good balance for most vegetables
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter2.4%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Bassett 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 50606; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Arlington, IA

Summer high83 °Faverage high, July
Winter low9 °Faverage low, January
Hot days9days a year at 90 °F or more
Freezing nights156nights a year at 32 °F or less
Growing degree days2,989base 50 °F — the season’s usable heat
Longest day15 h 20 mindaylight on June 21
Shortest day9 h 02 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation39.6 inper year, rain and melted snow
Snowfall40 inper year; 70 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 27 °F, low 9 °F 27°9° JanFebruary: average high 31 °F, low 12 °F 31°12° FebMarch: average high 45 °F, low 24 °F 45°24° MarApril: average high 59 °F, low 37 °F 59°37° AprMay: average high 71 °F, low 49 °F 71°49° MayJune: average high 81 °F, low 60 °F 81°60° JunJuly: average high 83 °F, low 63 °F 83°63° JulAugust: average high 81 °F, low 61 °F 81°61° AugSeptember: average high 76 °F, low 52 °F 76°52° SepOctober: average high 63 °F, low 40 °F 63°40° OctNovember: average high 46 °F, low 27 °F 46°27° NovDecember: average high 33 °F, low 16 °F 33°16° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 1.29 in precipitation, 8.9 in snowfall 1.3❄9 JanFebruary: 1.31 in precipitation, 11.7 in snowfall 1.3❄12 FebMarch: 2.11 in precipitation, 5.1 in snowfall 2.1❄5 MarApril: 4.22 in precipitation, 2.1 in snowfall 4.2❄2 AprMay: 5.08 in precipitation 5.1 MayJune: 5.96 in precipitation 6.0 JunJuly: 5.36 in precipitation 5.4 JulAugust: 3.71 in precipitation 3.7 AugSeptember: 3.63 in precipitation 3.6 SepOctober: 3.00 in precipitation, 0.3 in snowfall 3.0 OctNovember: 2.32 in precipitation, 2.4 in snowfall 2.3❄2 NovDecember: 1.64 in precipitation, 9.8 in snowfall 1.6❄10 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Oelwein 1e, IA (11 mi away); precipitation: Strawberry Pt, IA (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

521425a
Fayette, IA · 8 mi
521695a
Wadena, IA · 8 mi
520774b
Volga, IA · 8 mi
506715a
Stanley, IA · 9 mi
506505a
Lamont, IA · 9 mi
520764b
Strawberry Point, IA · 10 mi
506555a
Maynard, IA · 10 mi
506075a
Aurora, IA · 10 mi

Iowa planting zones →

Questions about 50606

What planting zone is ZIP code 50606?

ZIP code 50606 (Arlington, IA) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Arlington, IA?

The median last spring frost (32 °F) near 50606 is April 27; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Oelwein 1e station.

When is the first frost in Arlington, IA?

The median first fall frost near 50606 is October 13, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 50606?

Start tomato seeds indoors around Mar 2 – Mar 16 and set transplants outside around May 4 – May 18, one to three weeks after the median last frost.

How much rain and snow does 50606 get?

About 39.6 inches of precipitation a year and 40 inches of snowfall (NOAA 1991–2020 normals, Strawberry Pt station).

How hot do summers get in Arlington, IA?

The average high peaks at 83 °F in July, with about 9 days a year at 90 °F or more.

What kind of soil does 50606 have?

The USDA soil survey maps Bassett at the center of ZIP 50606: loam, moderately well drained, pH about 6.2 (slightly acidic).

Did spring come early in Arlington, IA in 2026?

Spring leaf-out near 50606 came on Mar 28 in 2026, 16 days earlier than the 1991–2020 average (Apr 13), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Arlington, IA?

Long-day onions: the longest day near 50606 is 15 h 20 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).