Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 68840 — Gibbon, NE

ZIP code 68840 (Gibbon, Buffalo County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 30 and the first fall frost October 10.

Where ZIP 68840 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 30

First frostOct 10

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 Gibbon, NE…

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 Gibbon, NE

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 12only 10% chance of frost after

First fall frostOctober 10median — 10% chance by Sep 25

Growing season162 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 19 and returns around October 19.

From the NOAA station Kearney 4 Ne, NE — 7 miles away, elevation 2,129 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 68840

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 15 – Aug 29

GarlicPlant cloves · Sep 26 – Oct 31

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 10) 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 68840 came on Mar 12 — 17 days earlier than the 1991–2020 average (Mar 29).

average
Mar 292026
Mar 12

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 Nebraska

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

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 Gibbon, NE.

Soil in Gibbon, NE

The soil mapped at the center of ZIP 68840 is Cozad — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH6.4slightly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupBwater soaks in moderately

Farmland classprime farmlandUSDA classification

Map unit: Cozad silt loam, 0 to 1 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 68840; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Gibbon, NE

Summer high87 °Faverage high, July

Winter low14 °Faverage low, January

Hot days31days a year at 90 °F or more

Freezing nights157nights a year at 32 °F or less

Growing degree days3,132base 50 °F — the season’s usable heat

Longest day15 h 06 mindaylight on June 21

Shortest day9 h 15 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation25.6 inper year, rain and melted snow

Snowfall22 inper year; 33 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Kearney 4 Ne, NE (7 mi away); precipitation: Kearney 4 Ne, NE (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

Heartwell, NE · 15 mi

688455b

Kearney, NE · 16 mi

688705b

Riverdale, NE · 16 mi

Nebraska planting zones →

Questions about 68840

What planting zone is ZIP code 68840?

ZIP code 68840 (Gibbon, NE) 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 Gibbon, NE?

The median last spring frost (32 °F) near 68840 is April 30; after May 12 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Kearney 4 Ne station.

When is the first frost in Gibbon, NE?

The median first fall frost near 68840 is October 10, giving a median frost-free growing season of 162 days.

When should I plant tomatoes in 68840?

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 68840 get?

About 25.6 inches of precipitation a year and 22 inches of snowfall (NOAA 1991–2020 normals, Kearney 4 Ne station).

How hot do summers get in Gibbon, NE?

The average high peaks at 87 °F in July, with about 31 days a year at 90 °F or more.

What kind of soil does 68840 have?

The USDA soil survey maps Cozad at the center of ZIP 68840: silt loam, well drained, pH about 6.4 (slightly acidic).

Did spring come early in Gibbon, NE in 2026?

Spring leaf-out near 68840 came on Mar 12 in 2026, 17 days earlier than the 1991–2020 average (Mar 29), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Gibbon, NE?

Long-day onions: the longest day near 68840 is 15 h 06 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).