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

Planting zone for 58338 — Hampden, ND

ZIP code 58338 (Hampden, Ramsey County) is in USDA zone 4a: the coldest winter night averages −30 to −25 °F. The median last spring frost is May 15 and the first fall frost September 22.

Where ZIP 58338 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.

Zone4a−30 to −25 °F

Coldest night−34.4 to −31.7 °C

Last frostMay 15

First frostSep 22

2012 zone3b

Was 3b 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 4a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Hampden, ND…

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 Hampden, ND

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 15median — 50% chance of a later frost

Safe for tender plantsMay 31only 10% chance of frost after

First fall frostSeptember 22median — 10% chance by Sep 11

Growing season128 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 4 and returns around October 1.

From the NOAA station Edmore 4nw, ND — 7 miles away, elevation 1,539 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 58338

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 3 – Apr 17

SpinachSow outdoors · Apr 3 – Apr 24

Broccoli, cabbageStart indoors · Mar 6 – Mar 20

Broccoli, cabbageTransplant · Apr 24 – May 8

Onion setsPlant outdoors · Apr 17 – May 1

PotatoesPlant outdoors · Apr 24 – May 8

LettuceSow outdoors · Apr 17 – May 1

Carrots, beetsSow outdoors · Apr 24 – May 8

TomatoesStart indoors · Mar 20 – Apr 3

TomatoesTransplant · May 22 – Jun 5

Peppers, eggplantStart indoors · Mar 6 – Mar 20

Peppers, eggplantTransplant · May 29 – Jun 12

BeansSow outdoors · May 22 – Jun 5

Sweet cornSow outdoors · May 22 – Jun 5

Cucumbers, squashSow outdoors · May 22 – Jun 5

Fall lettuce, spinachSow outdoors · Jul 28 – Aug 11

GarlicPlant cloves · Sep 8 – Oct 13

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 15) and first fall frost (Sep 22) 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 58338 came on May 6 — 8 days later than the 1991–2020 average (Apr 28).

average
Apr 282026
May 6

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 Hampden, ND

The soil mapped at the center of ZIP 58338 is Parnell — silty clay loam, very poorly drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up

pH7.0neutral; most vegetables like 6.0–7.0

DrainageVery poorly drainedconsider raised beds

Organic matter8%high

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Parnell-Vallers, saline, complex, 0 to 2 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 58338; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hampden, ND

Summer high78 °Faverage high, July

Winter low−6 °Faverage low, January

Hot days4days a year at 90 °F or more

Freezing nights197nights a year at 32 °F or less

Growing degree days1,787base 50 °F — the season’s usable heat

Longest day16 h 08 mindaylight on June 21

Shortest day8 h 17 mindaylight on December 21

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

Precipitation21.9 inper year, rain and melted snow

Snowfall38 inper year; 129 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: Edmore 4nw, ND (7 mi away); precipitation: Edmore 4nw, ND (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Starkweather, ND · 12 mi

North Dakota planting zones →

Questions about 58338

What planting zone is ZIP code 58338?

ZIP code 58338 (Hampden, ND) is in USDA hardiness zone 4a on the 2023 map: the coldest night of an average winter reaches −30 to −25 °F (−34.4 to −31.7 °C).

When is the last frost in Hampden, ND?

The median last spring frost (32 °F) near 58338 is May 15; after May 31 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Edmore 4nw station.

When is the first frost in Hampden, ND?

The median first fall frost near 58338 is September 22, giving a median frost-free growing season of 128 days.

When should I plant tomatoes in 58338?

Start tomato seeds indoors around Mar 20 – Apr 3 and set transplants outside around May 22 – Jun 5, one to three weeks after the median last frost.

How much rain and snow does 58338 get?

About 21.9 inches of precipitation a year and 38 inches of snowfall (NOAA 1991–2020 normals, Edmore 4nw station).

How hot do summers get in Hampden, ND?

The average high peaks at 78 °F in July, with about 4 days a year at 90 °F or more.

What kind of soil does 58338 have?

The USDA soil survey maps Parnell at the center of ZIP 58338: silty clay loam, very poorly drained, pH about 7.0 (neutral).

Did spring come early in Hampden, ND in 2026?

Spring leaf-out near 58338 came on May 6 in 2026, 8 days later than the 1991–2020 average (Apr 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Hampden, ND?

Long-day onions: the longest day near 58338 is 16 h 08 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 58338 change?

Yes. The 2012 USDA map put 58338 in zone 3b; the 2023 map puts it in zone 4a. The newer map uses 1991–2020 data and more weather stations.