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

Planting zone for 56521 — Callaway, MN

ZIP code 56521 (Callaway, Becker 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 24.

Where ZIP 56521 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 24

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 Callaway, MN…

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 Callaway, MN

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 30only 10% chance of frost after

First fall frostSeptember 24median — 10% chance by Sep 9

Growing season130 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 5 and returns around October 3.

From the NOAA station Detroit Lakes 1 Nne, MN — 12 miles away, elevation 1,355 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 56521

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 30 – Aug 13

GarlicPlant cloves · Sep 10 – Oct 15

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 15) and first fall frost (Sep 24) 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 56521 came on Apr 23 — about the same time as the 1991–2020 average (Apr 24).

average
Apr 242026
Apr 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).

Native plants for zone 4a in Minnesota

445 plants native to the lower 48 states, recorded in Minnesota, and rated by the USDA to survive −30 °F or colder — the bottom of zone 4a. Each links to its USDA PLANTS profile.

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 Callaway, MN.

Soil in Callaway, MN

The soil mapped at the center of ZIP 56521 is Aazdahl — clay loam, moderately well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up

pH7.0neutral; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter5%high

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Aazdahl-Formdale-Balaton clay loams, 0 to 4 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 56521; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Callaway, MN

Summer high79 °Faverage high, July

Winter low−4 °Faverage low, January

Hot days7days a year at 90 °F or more

Freezing nights177nights a year at 32 °F or less

Growing degree days2,049base 50 °F — the season’s usable heat

Longest day15 h 54 mindaylight on June 21

Shortest day8 h 30 mindaylight on December 21

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

Precipitation29.4 inper year, rain and melted snow

Snowfall48 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Detroit Lakes 1 Nne, MN (12 mi away); precipitation: Detroit Lakes 1 Nne, MN (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4a.

565694a

Ogema, MN · 7 mi

565914a

White Earth, MN · 7 mi

565014a

Detroit Lakes, MN · 12 mi

565114a

Audubon, MN · 12 mi

565544a

Lake Park, MN · 13 mi

565024a

Detroit Lakes, MN · 13 mi

565784a

Rochert, MN · 13 mi

565524a

Hitterdal, MN · 16 mi

Minnesota planting zones →

Questions about 56521

What planting zone is ZIP code 56521?

ZIP code 56521 (Callaway, MN) 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 Callaway, MN?

The median last spring frost (32 °F) near 56521 is May 15; after May 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Detroit Lakes 1 Nne station.

When is the first frost in Callaway, MN?

The median first fall frost near 56521 is September 24, giving a median frost-free growing season of 130 days.

When should I plant tomatoes in 56521?

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 56521 get?

About 29.4 inches of precipitation a year and 48 inches of snowfall (NOAA 1991–2020 normals, Detroit Lakes 1 Nne station).

How hot do summers get in Callaway, MN?

The average high peaks at 79 °F in July, with about 7 days a year at 90 °F or more.

What kind of soil does 56521 have?

The USDA soil survey maps Aazdahl at the center of ZIP 56521: clay loam, moderately well drained, pH about 7.0 (neutral).

Did spring come early in Callaway, MN in 2026?

Spring leaf-out near 56521 came on Apr 23 in 2026, about the same as the 1991–2020 average (Apr 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Callaway, MN?

Long-day onions: the longest day near 56521 is 15 h 54 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 56521 change?

Yes. The 2012 USDA map put 56521 in zone 3b; the 2023 map puts it in zone 4a. The newer map uses 1991–2020 data and more weather stations.