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

Planting zone for 68870 — Riverdale, NE

ZIP code 68870 (Riverdale, 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 68870 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 Riverdale, 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 Riverdale, 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 — 11 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 68870

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 68870 came on Mar 11 — 18 days earlier than the 1991–2020 average (Mar 29).

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 Riverdale, NE

The soil mapped at the center of ZIP 68870 is Hobbs — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH6.9neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: Hobbs silt loam, occasionally flooded, cool.

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 68870; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Riverdale, 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 07 mindaylight on June 21
Shortest day9 h 14 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation26 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 36 °F, low 14 °F 36°14° JanFebruary: average high 40 °F, low 17 °F 40°17° FebMarch: average high 51 °F, low 25 °F 51°25° MarApril: average high 62 °F, low 36 °F 62°36° AprMay: average high 72 °F, low 47 °F 72°47° MayJune: average high 82 °F, low 59 °F 82°59° JunJuly: average high 87 °F, low 63 °F 87°63° JulAugust: average high 84 °F, low 61 °F 84°61° AugSeptember: average high 78 °F, low 51 °F 78°51° SepOctober: average high 65 °F, low 38 °F 65°38° OctNovember: average high 51 °F, low 25 °F 51°25° NovDecember: average high 38 °F, low 17 °F 38°17° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 0.43 in precipitation 0.4 JanFebruary: 0.60 in precipitation 0.6 FebMarch: 1.48 in precipitation 1.5 MarApril: 2.62 in precipitation 2.6 AprMay: 4.17 in precipitation 4.2 MayJune: 3.91 in precipitation 3.9 JunJuly: 3.97 in precipitation 4.0 JulAugust: 3.20 in precipitation 3.2 AugSeptember: 1.95 in precipitation 1.9 SepOctober: 2.04 in precipitation 2.0 OctNovember: 0.88 in precipitation 0.9 NovDecember: 0.74 in precipitation 0.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Kearney 4 Ne, NE (11 mi away); precipitation: Riverdale 0.2 Wnw, NE (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

688125b
Amherst, NE · 8 mi
688665b
Pleasanton, NE · 9 mi
688455b
Kearney, NE · 9 mi
688475b
Kearney, NE · 10 mi
688495b
Kearney, NE · 10 mi
688615b
Odessa, NE · 12 mi
688485b
Kearney, NE · 12 mi
688585b
Miller, NE · 14 mi

Nebraska planting zones →

Questions about 68870

What planting zone is ZIP code 68870?

ZIP code 68870 (Riverdale, 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 Riverdale, NE?

The median last spring frost (32 °F) near 68870 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 Riverdale, NE?

The median first fall frost near 68870 is October 10, giving a median frost-free growing season of 162 days.

When should I plant tomatoes in 68870?

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 68870 get?

About 26 inches of precipitation a year (NOAA 1991–2020 normals, Riverdale 0.2 Wnw station).

How hot do summers get in Riverdale, 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 68870 have?

The USDA soil survey maps Hobbs at the center of ZIP 68870: silt loam, well drained, pH about 6.9 (neutral).

Did spring come early in Riverdale, NE in 2026?

Spring leaf-out near 68870 came on Mar 11 in 2026, 18 days earlier than the 1991–2020 average (Mar 29), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Riverdale, NE?

Long-day onions: the longest day near 68870 is 15 h 07 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).