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

Planting zone for Council Bluffs, IA

Council Bluffs, IA is in USDA zones 5b to 6a across its 3 ZIP codes. The median last spring frost is April 18 and the first fall frost October 21.

Council Bluffs on the zone map

Outlined: its 2 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.

Zones5b–6a−15 to −5 °F
ZIP codes3
Last frostApr 18
First frostOct 21
Growing season185 days

5b 1 ZIP   6a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Council Bluffs, 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 Council Bluffs, IA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 18median — 50% chance of a later frost
Safe for tender plantsApril 30only 10% chance of frost after
First fall frostOctober 21median — 10% chance by Oct 6
Growing season185 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 8 and returns around October 30.

From the NOAA station Omaha Eppley Airfield, NE, elevation 981 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 Council Bluffs

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 7 – Mar 21
SpinachSow outdoors · Mar 7 – Mar 28
Broccoli, cabbageStart indoors · Feb 7 – Feb 21
Broccoli, cabbageTransplant · Mar 28 – Apr 11
Onion setsPlant outdoors · Mar 21 – Apr 4
PotatoesPlant outdoors · Mar 28 – Apr 11
LettuceSow outdoors · Mar 21 – Apr 4
Carrots, beetsSow outdoors · Mar 28 – Apr 11
TomatoesStart indoors · Feb 21 – Mar 7
TomatoesTransplant · Apr 25 – May 9
Peppers, eggplantStart indoors · Feb 7 – Feb 21
Peppers, eggplantTransplant · May 2 – May 16
BeansSow outdoors · Apr 25 – May 9
Sweet cornSow outdoors · Apr 25 – May 9
Cucumbers, squashSow outdoors · Apr 25 – May 9
Fall lettuce, spinachSow outdoors · Aug 26 – Sep 9
GarlicPlant cloves · Oct 7 – Nov 11
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Oct 21) 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 51502 came on Mar 12 — 18 days earlier than the 1991–2020 average (Mar 30).

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 Iowa

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

Trees 49

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 191

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 136

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 Council Bluffs, IA.

Soil in Council Bluffs, IA

The soil mapped at the center of ZIP 51502 is Keg — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH6.7neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Keg-Urban land complex, 0 to 2 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 51502; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Council Bluffs, IA

Summer high88 °Faverage high, July
Winter low15 °Faverage low, January
Hot days33days a year at 90 °F or more
Freezing nights135nights a year at 32 °F or less
Growing degree days3,787base 50 °F — the season’s usable heat
Longest day15 h 09 mindaylight on June 21
Shortest day9 h 12 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation34.1 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 34 °F, low 15 °F 34°15° JanFebruary: average high 39 °F, low 19 °F 39°19° FebMarch: average high 52 °F, low 30 °F 52°30° MarApril: average high 64 °F, low 41 °F 64°41° AprMay: average high 75 °F, low 53 °F 75°53° MayJune: average high 84 °F, low 63 °F 84°63° JunJuly: average high 88 °F, low 68 °F 88°68° JulAugust: average high 86 °F, low 66 °F 86°66° AugSeptember: average high 79 °F, low 56 °F 79°56° SepOctober: average high 66 °F, low 43 °F 66°43° OctNovember: average high 50 °F, low 30 °F 50°30° NovDecember: average high 38 °F, low 20 °F 38°20° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 0.83 in precipitation 0.8 JanFebruary: 1.06 in precipitation 1.1 FebMarch: 1.87 in precipitation 1.9 MarApril: 3.41 in precipitation 3.4 AprMay: 5.34 in precipitation 5.3 MayJune: 4.99 in precipitation 5.0 JunJuly: 3.75 in precipitation 3.8 JulAugust: 3.86 in precipitation 3.9 AugSeptember: 3.42 in precipitation 3.4 SepOctober: 2.67 in precipitation 2.7 OctNovember: 1.45 in precipitation 1.4 NovDecember: 1.44 in precipitation 1.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Omaha Eppley Airfield, NE (4 mi away); precipitation: Council Bluffs 3.4 Nne, IA (2 mi away). Daylight is calculated from latitude.

ZIP codes in Council Bluffs

515015b
−15 to −10 °F
515026a
−10 to −5 °F
515036a
−10 to −5 °F

Iowa planting zones →

Questions about Council Bluffs

What planting zone is Council Bluffs, IA?

Council Bluffs, IA is in USDA hardiness zones 5b to 6a on the 2023 map (5b: −15 to −10 °F; 6a: −10 to −5 °F).

When is the last frost in Council Bluffs, IA?

The median last spring frost is April 18 and the median first fall frost is October 21 (NOAA 1991–2020 normals, Omaha Eppley Airfield station).

When can I plant a garden in Council Bluffs, IA?

Cool-season crops like peas and spinach go in around Mar 7 – Mar 28; tomatoes, peppers, beans and squash after about Apr 25, once frost risk has passed.

What kind of onions grow in Council Bluffs, IA?

Long-day onions: the longest day is 15 h 09 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Council Bluffs, IA get?

About 34.1 inches of precipitation a year (NOAA 1991–2020 normals).