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

Planting zone for 62501 — Argenta, IL

ZIP code 62501 (Argenta, Macon County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 16 and the first fall frost October 22.

Where ZIP 62501 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 16

First frostOct 22

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 Argenta, 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 Argenta, IL

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 16median — 50% chance of a later frost

Safe for tender plantsApril 30only 10% chance of frost after

First fall frostOctober 22median — 10% chance by Oct 7

Growing season187 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around November 2.

From the NOAA station Decatur Airport, IL — 7 miles away, elevation 676 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 62501

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 5 – Mar 19

SpinachSow outdoors · Mar 5 – Mar 26

Broccoli, cabbageStart indoors · Feb 5 – Feb 19

Broccoli, cabbageTransplant · Mar 26 – Apr 9

Onion setsPlant outdoors · Mar 19 – Apr 2

PotatoesPlant outdoors · Mar 26 – Apr 9

LettuceSow outdoors · Mar 19 – Apr 2

Carrots, beetsSow outdoors · Mar 26 – Apr 9

TomatoesStart indoors · Feb 19 – Mar 5

TomatoesTransplant · Apr 23 – May 7

Peppers, eggplantStart indoors · Feb 5 – Feb 19

Peppers, eggplantTransplant · Apr 30 – May 14

BeansSow outdoors · Apr 23 – May 7

Sweet cornSow outdoors · Apr 23 – May 7

Cucumbers, squashSow outdoors · Apr 23 – May 7

Fall lettuce, spinachSow outdoors · Aug 27 – Sep 10

GarlicPlant cloves · Oct 8 – Nov 12

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 16) and first fall frost (Oct 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 62501 came on Mar 11 — 15 days earlier than the 1991–2020 average (Mar 26).

average
Mar 262026
Mar 11

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 Illinois

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

Soil in Argenta, IL

The soil mapped at the center of ZIP 62501 is Birkbeck — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables

pH6.1slightly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter2.5%moderate

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Birkbeck silt loam, 2 to 5 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 62501; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Argenta, IL

Summer high86 °Faverage high, July

Winter low20 °Faverage low, January

Hot days27days a year at 90 °F or more

Freezing nights113nights a year at 32 °F or less

Growing degree days3,646base 50 °F — the season’s usable heat

Longest day15 h 00 mindaylight on June 21

Shortest day9 h 20 mindaylight on December 21

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

Precipitation36.4 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Decatur Airport, IL (7 mi away); precipitation: Decatur Airport, IL (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

625546a

Oreana, IL · 4 mi

618186a

Cerro Gordo, IL · 6 mi

Illinois planting zones →

Questions about 62501

What planting zone is ZIP code 62501?

ZIP code 62501 (Argenta, IL) 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 Argenta, IL?

The median last spring frost (32 °F) near 62501 is April 16; after April 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Decatur Airport station.

When is the first frost in Argenta, IL?

The median first fall frost near 62501 is October 22, giving a median frost-free growing season of 187 days.

When should I plant tomatoes in 62501?

Start tomato seeds indoors around Feb 19 – Mar 5 and set transplants outside around Apr 23 – May 7, one to three weeks after the median last frost.

How much rain and snow does 62501 get?

About 36.4 inches of precipitation a year (NOAA 1991–2020 normals, Decatur Airport station).

How hot do summers get in Argenta, IL?

The average high peaks at 86 °F in July, with about 27 days a year at 90 °F or more.

What kind of soil does 62501 have?

The USDA soil survey maps Birkbeck at the center of ZIP 62501: silt loam, moderately well drained, pH about 6.1 (slightly acidic).

Did spring come early in Argenta, IL in 2026?

Spring leaf-out near 62501 came on Mar 11 in 2026, 15 days earlier than the 1991–2020 average (Mar 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Argenta, IL?

Long-day onions: the longest day near 62501 is 15 h 00 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 62501 change?

Yes. The 2012 USDA map put 62501 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.