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

Planting zone for 68976 — Smithfield, NE

ZIP code 68976 (Smithfield, Gosper County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 26 and the first fall frost October 13.

Where ZIP 68976 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 26
First frostOct 13
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 Smithfield, 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 Smithfield, NE

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 26median — 50% chance of a later frost
Safe for tender plantsMay 7only 10% chance of frost after
First fall frostOctober 13median — 10% chance by Sep 29
Growing season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 14 and returns around October 21.

From the NOAA station Canaday Steam Plt, NE — 6 miles away, elevation 2,362 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 68976

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 15 – Mar 29
SpinachSow outdoors · Mar 15 – Apr 5
Broccoli, cabbageStart indoors · Feb 15 – Mar 1
Broccoli, cabbageTransplant · Apr 5 – Apr 19
Onion setsPlant outdoors · Mar 29 – Apr 12
PotatoesPlant outdoors · Apr 5 – Apr 19
LettuceSow outdoors · Mar 29 – Apr 12
Carrots, beetsSow outdoors · Apr 5 – Apr 19
TomatoesStart indoors · Mar 1 – Mar 15
TomatoesTransplant · May 3 – May 17
Peppers, eggplantStart indoors · Feb 15 – Mar 1
Peppers, eggplantTransplant · May 10 – May 24
BeansSow outdoors · May 3 – May 17
Sweet cornSow outdoors · May 3 – May 17
Cucumbers, squashSow outdoors · May 3 – May 17
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 26) 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 68976 came on Mar 8 — 20 days earlier than the 1991–2020 average (Mar 28).

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.

Trees 31

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Fbitternut hickory75 ft · blooms mid spring · high shade tolerance · to −47 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fblack oak80 ft · blooms early spring · medium shade tolerance · to −30 °F

Shrubs 55

alderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °Fbig sagebrush4 ft · blooms mid summer · high shade tolerance · to −43 °F

Wildflowers & perennials 190

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °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 °FAmerican speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °F

Grasses 130

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbasin wildrye5 ft · blooms early spring · high shade tolerance · to −43 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °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 °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 Smithfield, NE.

Soil in Smithfield, NE

The soil mapped at the center of ZIP 68976 is Hall — 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 groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Hall 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 68976; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Smithfield, NE

Summer high86 °Faverage high, July
Winter low15 °Faverage low, January
Hot days29days a year at 90 °F or more
Freezing nights154nights a year at 32 °F or less
Growing degree days3,214base 50 °F — the season’s usable heat
Longest day15 h 05 mindaylight on June 21
Shortest day9 h 16 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation23.4 inper year, rain and melted snow
Snowfall20 inper year

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 38 °F, low 15 °F 38°15° JanFebruary: average high 41 °F, low 18 °F 41°18° FebMarch: average high 53 °F, low 27 °F 53°27° MarApril: average high 62 °F, low 37 °F 62°37° AprMay: average high 72 °F, low 48 °F 72°48° MayJune: average high 82 °F, low 59 °F 82°59° JunJuly: average high 86 °F, low 64 °F 86°64° JulAugust: average high 84 °F, low 62 °F 84°62° AugSeptember: average high 78 °F, low 52 °F 78°52° SepOctober: average high 65 °F, low 38 °F 65°38° OctNovember: average high 51 °F, low 26 °F 51°26° NovDecember: average high 40 °F, low 18 °F 40°18° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 0.43 in precipitation, 5.9 in snowfall 0.4❄6 JanFebruary: 0.51 in precipitation, 4.9 in snowfall 0.5❄5 FebMarch: 1.18 in precipitation, 2.3 in snowfall 1.2❄2 MarApril: 2.48 in precipitation, 1 in snowfall 2.5❄1 AprMay: 3.76 in precipitation, 0.1 in snowfall 3.8 MayJune: 3.86 in precipitation 3.9 JunJuly: 3.29 in precipitation 3.3 JulAugust: 2.99 in precipitation 3.0 AugSeptember: 1.81 in precipitation 1.8 SepOctober: 1.74 in precipitation, 0.6 in snowfall 1.7❄1 OctNovember: 0.74 in precipitation, 1.9 in snowfall 0.7❄2 NovDecember: 0.60 in precipitation, 3.3 in snowfall 0.6❄3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Canaday Steam Plt, NE (6 mi away); precipitation: Canaday Steam Plt, NE (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

689276a
Bertrand, NE · 8 mi
689375b
Elwood, NE · 8 mi
689585b
Loomis, NE · 12 mi
688635b
Overton, NE · 15 mi
688505b
Lexington, NE · 16 mi
688365b
Elm Creek, NE · 19 mi
689366a
Edison, NE · 20 mi
689496a
Holdrege, NE · 20 mi

Nebraska planting zones →

Questions about 68976

What planting zone is ZIP code 68976?

ZIP code 68976 (Smithfield, 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 Smithfield, NE?

The median last spring frost (32 °F) near 68976 is April 26; after May 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Canaday Steam Plt station.

When is the first frost in Smithfield, NE?

The median first fall frost near 68976 is October 13, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 68976?

Start tomato seeds indoors around Mar 1 – Mar 15 and set transplants outside around May 3 – May 17, one to three weeks after the median last frost.

How much rain and snow does 68976 get?

About 23.4 inches of precipitation a year and 20 inches of snowfall (NOAA 1991–2020 normals, Canaday Steam Plt station).

How hot do summers get in Smithfield, 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 68976 have?

The USDA soil survey maps Hall at the center of ZIP 68976: silt loam, well drained, pH about 6.7 (neutral).

Did spring come early in Smithfield, NE in 2026?

Spring leaf-out near 68976 came on Mar 8 in 2026, 20 days earlier than the 1991–2020 average (Mar 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Smithfield, NE?

Long-day onions: the longest day near 68976 is 15 h 05 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).