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

Planting zone for 68337 — Dawson, NE

ZIP code 68337 (Dawson, Richardson County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 18 and the first fall frost October 17.

Where ZIP 68337 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostApr 18
First frostOct 17
2012 zone5b

Was 5b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Dawson, 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 Dawson, NE

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 18median — 50% chance of a later frost
Safe for tender plantsMay 2only 10% chance of frost after
First fall frostOctober 17median — 10% chance by Oct 1
Growing season180 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 8 and returns around October 26.

From the NOAA station Falls City Brenner Field, NE — 13 miles away, elevation 981 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 68337

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 7 – Mar 21
SpinachSow outdoors · Mar 7 – Mar 28
Broccoli, cabbageStart indoors · Feb 7 – Feb 21
Broccoli, cabbageTransplant · Mar 28 – Apr 11
Onion setsPlant outdoors · Mar 21 – Apr 4
PotatoesPlant outdoors · Mar 28 – Apr 11
LettuceSow outdoors · Mar 21 – Apr 4
Carrots, beetsSow outdoors · Mar 28 – Apr 11
TomatoesStart indoors · Feb 21 – Mar 7
TomatoesTransplant · Apr 25 – May 9
Peppers, eggplantStart indoors · Feb 7 – Feb 21
Peppers, eggplantTransplant · May 2 – May 16
BeansSow outdoors · Apr 25 – May 9
Sweet cornSow outdoors · Apr 25 – May 9
Cucumbers, squashSow outdoors · Apr 25 – May 9
Fall lettuce, spinachSow outdoors · Aug 22 – Sep 5
GarlicPlant cloves · Oct 3 – Nov 7
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Oct 17) 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 68337 came on Mar 11 — 14 days earlier than the 1991–2020 average (Mar 25).

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 6a in Nebraska

432 plants native to the lower 48 states, recorded in Nebraska, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. 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 57

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 198

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 8

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 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °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 Dawson, NE.

Soil in Dawson, NE

The soil mapped at the center of ZIP 68337 is Wymore — silty clay loam, moderately well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH6.0slightly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter3%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classprime farmlandUSDA classification

Map unit: Wymore silty clay loam, 3 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 68337; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Dawson, NE

Summer high88 °Faverage high, July
Winter low17 °Faverage low, January
Hot days41days a year at 90 °F or more
Freezing nights131nights a year at 32 °F or less
Growing degree days3,775base 50 °F — the season’s usable heat
Longest day15 h 02 mindaylight on June 21
Shortest day9 h 19 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation35.1 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 36 °F, low 17 °F 36°17° JanFebruary: average high 42 °F, low 21 °F 42°21° FebMarch: average high 54 °F, low 31 °F 54°31° MarApril: average high 65 °F, low 41 °F 65°41° AprMay: average high 75 °F, low 53 °F 75°53° MayJune: average high 85 °F, low 63 °F 85°63° JunJuly: average high 88 °F, low 66 °F 88°66° JulAugust: average high 87 °F, low 64 °F 87°64° AugSeptember: average high 80 °F, low 55 °F 80°55° SepOctober: average high 67 °F, low 43 °F 67°43° OctNovember: average high 52 °F, low 30 °F 52°30° NovDecember: average high 40 °F, low 21 °F 40°21° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 0.88 in precipitation 0.9 JanFebruary: 1.30 in precipitation 1.3 FebMarch: 2.23 in precipitation 2.2 MarApril: 3.26 in precipitation 3.3 AprMay: 5.01 in precipitation 5.0 MayJune: 5.43 in precipitation 5.4 JunJuly: 4.54 in precipitation 4.5 JulAugust: 3.50 in precipitation 3.5 AugSeptember: 3.13 in precipitation 3.1 SepOctober: 2.72 in precipitation 2.7 OctNovember: 1.85 in precipitation 1.9 NovDecember: 1.24 in precipitation 1.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Falls City Brenner Field, NE (13 mi away); precipitation: Dawson 2.5 Se, NE (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

684336a
Salem, NE · 6 mi
683766a
Humboldt, NE · 8 mi
684576a
Verdon, NE · 8 mi
684426a
Stella, NE · 10 mi
683456a
Du Bois, NE · 11 mi
664086a
Bern, KS · 13 mi
665156a
Morrill, KS · 13 mi
683556a
Falls City, NE · 14 mi

Nebraska planting zones →

Questions about 68337

What planting zone is ZIP code 68337?

ZIP code 68337 (Dawson, NE) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Dawson, NE?

The median last spring frost (32 °F) near 68337 is April 18; after May 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Falls City Brenner Field station.

When is the first frost in Dawson, NE?

The median first fall frost near 68337 is October 17, giving a median frost-free growing season of 180 days.

When should I plant tomatoes in 68337?

Start tomato seeds indoors around Feb 21 – Mar 7 and set transplants outside around Apr 25 – May 9, one to three weeks after the median last frost.

How much rain and snow does 68337 get?

About 35.1 inches of precipitation a year (NOAA 1991–2020 normals, Dawson 2.5 Se station).

How hot do summers get in Dawson, NE?

The average high peaks at 88 °F in July, with about 41 days a year at 90 °F or more.

What kind of soil does 68337 have?

The USDA soil survey maps Wymore at the center of ZIP 68337: silty clay loam, moderately well drained, pH about 6.0 (slightly acidic).

Did spring come early in Dawson, NE in 2026?

Spring leaf-out near 68337 came on Mar 11 in 2026, 14 days earlier than the 1991–2020 average (Mar 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Dawson, NE?

Long-day onions: the longest day near 68337 is 15 h 02 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 68337 change?

Yes. The 2012 USDA map put 68337 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.