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

Planting zone for 62047 — Hardin, IL

ZIP code 62047 (Hardin, Calhoun County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 20 and the first fall frost October 20.

Where ZIP 62047 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.

Zone6b−5 to 0 °F

Coldest night−20.6 to −17.8 °C

Last frostApr 20

First frostOct 20

2012 zone6a

Was 6a 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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Hardin, IL…

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 Hardin, IL

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 20median — 50% chance of a later frost

Safe for tender plantsMay 5only 10% chance of frost after

First fall frostOctober 20median — 10% chance by Oct 6

Growing season181 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 6 and returns around October 29.

From the NOAA station Elsberry 1 S, MO — 9 miles away, elevation 476 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 62047

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 9 – Mar 23

SpinachSow outdoors · Mar 9 – Mar 30

Broccoli, cabbageStart indoors · Feb 9 – Feb 23

Broccoli, cabbageTransplant · Mar 30 – Apr 13

Onion setsPlant outdoors · Mar 23 – Apr 6

PotatoesPlant outdoors · Mar 30 – Apr 13

LettuceSow outdoors · Mar 23 – Apr 6

Carrots, beetsSow outdoors · Mar 30 – Apr 13

TomatoesStart indoors · Feb 23 – Mar 9

TomatoesTransplant · Apr 27 – May 11

Peppers, eggplantStart indoors · Feb 9 – Feb 23

Peppers, eggplantTransplant · May 4 – May 18

BeansSow outdoors · Apr 27 – May 11

Sweet cornSow outdoors · Apr 27 – May 11

Cucumbers, squashSow outdoors · Apr 27 – May 11

Fall lettuce, spinachSow outdoors · Aug 25 – Sep 8

GarlicPlant cloves · Oct 6 – Nov 10

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 20) and first fall frost (Oct 20) 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 62047 came on Mar 6 — 13 days earlier than the 1991–2020 average (Mar 19).

average
Mar 192026
Mar 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 Hardin, IL

The soil mapped at the center of ZIP 62047 is Goss — gravelly silt loam, well drained.

TextureGravelly silt loama good balance for most vegetables

pH5.5moderately acidic; 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: Goss gravelly silt loam, 35 to 60 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 62047; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hardin, IL

Summer high87 °Faverage high, July

Winter low20 °Faverage low, January

Hot days42days a year at 90 °F or more

Freezing nights107nights a year at 32 °F or less

Growing degree days3,788base 50 °F — the season’s usable heat

Longest day14 h 55 mindaylight on June 21

Shortest day9 h 25 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation41.3 inper year, rain and melted snow

Snowfall16 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Elsberry 1 S, MO (9 mi away); precipitation: Elsberry 1 S, MO (9 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.

Illinois planting zones →

Questions about 62047

What planting zone is ZIP code 62047?

ZIP code 62047 (Hardin, IL) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Hardin, IL?

The median last spring frost (32 °F) near 62047 is April 20; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Elsberry 1 S station.

When is the first frost in Hardin, IL?

The median first fall frost near 62047 is October 20, giving a median frost-free growing season of 181 days.

When should I plant tomatoes in 62047?

Start tomato seeds indoors around Feb 23 – Mar 9 and set transplants outside around Apr 27 – May 11, one to three weeks after the median last frost.

How much rain and snow does 62047 get?

About 41.3 inches of precipitation a year and 16 inches of snowfall (NOAA 1991–2020 normals, Elsberry 1 S station).

How hot do summers get in Hardin, IL?

The average high peaks at 87 °F in July, with about 42 days a year at 90 °F or more.

What kind of soil does 62047 have?

The USDA soil survey maps Goss at the center of ZIP 62047: gravelly silt loam, well drained, pH about 5.5 (moderately acidic).

Did spring come early in Hardin, IL in 2026?

Spring leaf-out near 62047 came on Mar 6 in 2026, 13 days earlier than the 1991–2020 average (Mar 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Hardin, IL?

Intermediate onions: the longest day near 62047 is 14 h 55 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 62047 change?

Yes. The 2012 USDA map put 62047 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.