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

Planting zone for 68774 — Saint Helena, NE

ZIP code 68774 (Saint Helena, Cedar County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 27 and the first fall frost October 11.

Where ZIP 68774 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 frostApr 27

First frostOct 11

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 Saint Helena, 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 Saint Helena, NE

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 11median — 10% chance by Sep 27

Growing season164 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 18 and returns around October 21.

From the NOAA station Yankton 2 E, SD — 6 miles away, elevation 1,181 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 68774

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 16 – Aug 30

GarlicPlant cloves · Sep 27 – Nov 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 27) and first fall frost (Oct 11) 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 68774 came on Mar 23 — 15 days earlier than the 1991–2020 average (Apr 7).

average
Apr 72026
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).

Soil in Saint Helena, NE

The soil mapped at the center of ZIP 68774 is Crofton — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH8.0alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Crofton-Nora complex, 6 to 11 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 68774; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Saint Helena, NE

Summer high87 °Faverage high, July

Winter low10 °Faverage low, January

Hot days33days a year at 90 °F or more

Freezing nights158nights a year at 32 °F or less

Growing degree days3,169base 50 °F — the season’s usable heat

Longest day15 h 20 mindaylight on June 21

Shortest day9 h 01 mindaylight on December 21

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

Precipitation30.7 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Yankton 2 E, SD (6 mi away); precipitation: St. Helena 4.1 Sw, NE (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Mission Hill, SD · 10 mi

Hartington, NE · 13 mi

687305a

Crofton, NE · 14 mi

Nebraska planting zones →

Questions about 68774

What planting zone is ZIP code 68774?

ZIP code 68774 (Saint Helena, 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 Saint Helena, NE?

The median last spring frost (32 °F) near 68774 is April 27; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Yankton 2 E station.

When is the first frost in Saint Helena, NE?

The median first fall frost near 68774 is October 11, giving a median frost-free growing season of 164 days.

When should I plant tomatoes in 68774?

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 68774 get?

About 30.7 inches of precipitation a year (NOAA 1991–2020 normals, St. Helena 4.1 Sw station).

How hot do summers get in Saint Helena, NE?

The average high peaks at 87 °F in July, with about 33 days a year at 90 °F or more.

What kind of soil does 68774 have?

The USDA soil survey maps Crofton at the center of ZIP 68774: silt loam, well drained, pH about 8.0 (alkaline).

Did spring come early in Saint Helena, NE in 2026?

Spring leaf-out near 68774 came on Mar 23 in 2026, 15 days earlier than the 1991–2020 average (Apr 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Saint Helena, NE?

Long-day onions: the longest day near 68774 is 15 h 20 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).