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

Planting zone for 68770 — Ponca, NE

ZIP code 68770 (Ponca, Dixon County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 3 and the first fall frost October 3.

Where ZIP 68770 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 frostMay 3

First frostOct 3

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 Ponca, 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 Ponca, NE

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMay 3median — 50% chance of a later frost

Safe for tender plantsMay 16only 10% chance of frost after

First fall frostOctober 3median — 10% chance by Sep 20

Growing season153 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 24 and returns around October 15.

From the NOAA station Vermillion 2 Se, SD — 16 miles away, elevation 1,139 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 68770

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 22 – Apr 5

SpinachSow outdoors · Mar 22 – Apr 12

Broccoli, cabbageStart indoors · Feb 22 – Mar 8

Broccoli, cabbageTransplant · Apr 12 – Apr 26

Onion setsPlant outdoors · Apr 5 – Apr 19

PotatoesPlant outdoors · Apr 12 – Apr 26

LettuceSow outdoors · Apr 5 – Apr 19

Carrots, beetsSow outdoors · Apr 12 – Apr 26

TomatoesStart indoors · Mar 8 – Mar 22

TomatoesTransplant · May 10 – May 24

Peppers, eggplantStart indoors · Feb 22 – Mar 8

Peppers, eggplantTransplant · May 17 – May 31

BeansSow outdoors · May 10 – May 24

Sweet cornSow outdoors · May 10 – May 24

Cucumbers, squashSow outdoors · May 10 – May 24

Fall lettuce, spinachSow outdoors · Aug 8 – Aug 22

GarlicPlant cloves · Sep 19 – Oct 24

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 3) and first fall frost (Oct 3) 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 68770 came on Mar 23 — 14 days earlier than the 1991–2020 average (Apr 6).

average
Apr 62026
Mar 23

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 Nebraska

413 plants native to the lower 48 states, recorded in Nebraska, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. 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 Ponca, NE.

Soil in Ponca, NE

The soil mapped at the center of ZIP 68770 is Crofton — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH7.7slightly alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Crofton silt loam, 17 to 30 percent slopes, eroded.

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 68770; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Ponca, NE

Summer high86 °Faverage high, July

Winter low10 °Faverage low, January

Hot days29days a year at 90 °F or more

Freezing nights152nights a year at 32 °F or less

Growing degree days3,160base 50 °F — the season’s usable heat

Longest day15 h 19 mindaylight on June 21

Shortest day9 h 03 mindaylight on December 21

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

Precipitation30.3 inper year, rain and melted snow

Snowfall36 inper year; 62 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: Vermillion 2 Se, SD (16 mi away); precipitation: Newcastle, NE (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

Jefferson, SD · 10 mi

687575a

Newcastle, NE · 10 mi

570255a

Elk Point, SD · 11 mi

687325a

Dixon, NE · 12 mi

570495a

North Sioux City, SD · 13 mi

Nebraska planting zones →

Questions about 68770

What planting zone is ZIP code 68770?

ZIP code 68770 (Ponca, NE) 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 Ponca, NE?

The median last spring frost (32 °F) near 68770 is May 3; after May 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Vermillion 2 Se station.

When is the first frost in Ponca, NE?

The median first fall frost near 68770 is October 3, giving a median frost-free growing season of 153 days.

When should I plant tomatoes in 68770?

Start tomato seeds indoors around Mar 8 – Mar 22 and set transplants outside around May 10 – May 24, one to three weeks after the median last frost.

How much rain and snow does 68770 get?

About 30.3 inches of precipitation a year and 36 inches of snowfall (NOAA 1991–2020 normals, Newcastle station).

How hot do summers get in Ponca, NE?

The average high peaks at 86 °F in July, with about 29 days a year at 90 °F or more.

What kind of soil does 68770 have?

The USDA soil survey maps Crofton at the center of ZIP 68770: silt loam, well drained, pH about 7.7 (slightly alkaline).

Did spring come early in Ponca, NE in 2026?

Spring leaf-out near 68770 came on Mar 23 in 2026, 14 days earlier than the 1991–2020 average (Apr 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Ponca, NE?

Long-day onions: the longest day near 68770 is 15 h 19 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).