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

Planting zone for 62830 — Dix, IL

ZIP code 62830 (Dix, Jefferson County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 9 and the first fall frost October 24.

Where ZIP 62830 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 9

First frostOct 24

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 Dix, 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 Dix, IL

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 9median — 50% chance of a later frost

Safe for tender plantsApril 25only 10% chance of frost after

First fall frostOctober 24median — 10% chance by Oct 10

Growing season196 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 30 and returns around November 2.

From the NOAA station Iuka 12 Sw, IL — 4 miles away, elevation 591 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 62830

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 26 – Mar 12

SpinachSow outdoors · Feb 26 – Mar 19

Broccoli, cabbageStart indoors · Jan 29 – Feb 12

Broccoli, cabbageTransplant · Mar 19 – Apr 2

Onion setsPlant outdoors · Mar 12 – Mar 26

PotatoesPlant outdoors · Mar 19 – Apr 2

LettuceSow outdoors · Mar 12 – Mar 26

Carrots, beetsSow outdoors · Mar 19 – Apr 2

TomatoesStart indoors · Feb 12 – Feb 26

TomatoesTransplant · Apr 16 – Apr 30

Peppers, eggplantStart indoors · Jan 29 – Feb 12

Peppers, eggplantTransplant · Apr 23 – May 7

BeansSow outdoors · Apr 16 – Apr 30

Sweet cornSow outdoors · Apr 16 – Apr 30

Cucumbers, squashSow outdoors · Apr 16 – Apr 30

Fall lettuce, spinachSow outdoors · Aug 29 – Sep 12

GarlicPlant cloves · Oct 10 – Nov 14

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 9) and first fall frost (Oct 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 62830 came on Mar 6 — 12 days earlier than the 1991–2020 average (Mar 18).

average
Mar 182026
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).

Native plants for zone 6b in Illinois

620 plants native to the lower 48 states, recorded in Illinois, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 Dix, IL.

Soil in Dix, IL

The soil mapped at the center of ZIP 62830 is Blair — silty clay loam, somewhat poorly drained.

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

pH6.2slightly acidic; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter0.75%low — add compost

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Blair silty clay loam, 5 to 10 percent slopes, severely 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 62830; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Dix, IL

Summer high88 °Faverage high, July

Winter low21 °Faverage low, January

Hot days33days a year at 90 °F or more

Freezing nights109nights a year at 32 °F or less

Growing degree days3,921base 50 °F — the season’s usable heat

Longest day14 h 51 mindaylight on June 21

Shortest day9 h 29 mindaylight on December 21

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

Precipitation44.2 inper year, rain and melted snow

Snowfall10 inper year; 13 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: Iuka 12 Sw, IL (4 mi away); precipitation: Dix, IL (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

628936b

Walnut Hill, IL · 4 mi

Mount Vernon, IL · 9 mi

628016b

Centralia, IL · 10 mi

628486b

Irvington, IL · 11 mi

628776b

Richview, IL · 13 mi

Illinois planting zones →

Questions about 62830

What planting zone is ZIP code 62830?

ZIP code 62830 (Dix, 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 Dix, IL?

The median last spring frost (32 °F) near 62830 is April 9; after April 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Iuka 12 Sw station.

When is the first frost in Dix, IL?

The median first fall frost near 62830 is October 24, giving a median frost-free growing season of 196 days.

When should I plant tomatoes in 62830?

Start tomato seeds indoors around Feb 12 – Feb 26 and set transplants outside around Apr 16 – Apr 30, one to three weeks after the median last frost.

How much rain and snow does 62830 get?

About 44.2 inches of precipitation a year and 10 inches of snowfall (NOAA 1991–2020 normals, Dix station).

How hot do summers get in Dix, IL?

The average high peaks at 88 °F in July, with about 33 days a year at 90 °F or more.

What kind of soil does 62830 have?

The USDA soil survey maps Blair at the center of ZIP 62830: silty clay loam, somewhat poorly drained, pH about 6.2 (slightly acidic).

Did spring come early in Dix, IL in 2026?

Spring leaf-out near 62830 came on Mar 6 in 2026, 12 days earlier than the 1991–2020 average (Mar 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Dix, IL?

Intermediate onions: the longest day near 62830 is 14 h 51 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 62830 change?

Yes. The 2012 USDA map put 62830 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.