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

Planting zone for 62842 — Geff, IL

ZIP code 62842 (Geff, Wayne County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 7 and the first fall frost October 26.

Where ZIP 62842 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 7
First frostOct 26
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 Geff, 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 Geff, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 7median — 50% chance of a later frost
Safe for tender plantsApril 23only 10% chance of frost after
First fall frostOctober 26median — 10% chance by Oct 14
Growing season201 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 27 and returns around November 6.

From the NOAA station Fairfield Radio Wfiw, IL — 7 miles away, elevation 430 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 62842

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 24 – Mar 10
SpinachSow outdoors · Feb 24 – Mar 17
Broccoli, cabbageStart indoors · Jan 27 – Feb 10
Broccoli, cabbageTransplant · Mar 17 – Mar 31
Onion setsPlant outdoors · Mar 10 – Mar 24
PotatoesPlant outdoors · Mar 17 – Mar 31
LettuceSow outdoors · Mar 10 – Mar 24
Carrots, beetsSow outdoors · Mar 17 – Mar 31
TomatoesStart indoors · Feb 10 – Feb 24
TomatoesTransplant · Apr 14 – Apr 28
Peppers, eggplantStart indoors · Jan 27 – Feb 10
Peppers, eggplantTransplant · Apr 21 – May 5
BeansSow outdoors · Apr 14 – Apr 28
Sweet cornSow outdoors · Apr 14 – Apr 28
Cucumbers, squashSow outdoors · Apr 14 – Apr 28
Fall lettuce, spinachSow outdoors · Aug 31 – Sep 14
GarlicPlant cloves · Oct 12 – Nov 16
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 7) and first fall frost (Oct 26) 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 62842 came on Mar 6 — 9 days earlier than the 1991–2020 average (Mar 15).

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 Geff, IL

The soil mapped at the center of ZIP 62842 is Passport — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH7.0neutral; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter1.6%low — add compost
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Passport silt loam, 5 to 10 percent slopes, 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 62842; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Geff, IL

Summer high90 °Faverage high, July
Winter low25 °Faverage low, January
Hot days44days a year at 90 °F or more
Freezing nights99nights a year at 32 °F or less
Growing degree days4,412base 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
Precipitation47 inper year, rain and melted snow
Snowfall12 inper year

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 41 °F, low 25 °F 41°25° JanFebruary: average high 47 °F, low 28 °F 47°28° FebMarch: average high 57 °F, low 36 °F 57°36° MarApril: average high 69 °F, low 47 °F 69°47° AprMay: average high 78 °F, low 56 °F 78°56° MayJune: average high 87 °F, low 64 °F 87°64° JunJuly: average high 90 °F, low 68 °F 90°68° JulAugust: average high 89 °F, low 66 °F 89°66° AugSeptember: average high 83 °F, low 58 °F 83°58° SepOctober: average high 71 °F, low 47 °F 71°47° OctNovember: average high 56 °F, low 36 °F 56°36° NovDecember: average high 45 °F, low 29 °F 45°29° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 3.52 in precipitation, 3.4 in snowfall 3.5❄3 JanFebruary: 2.50 in precipitation, 2.9 in snowfall 2.5❄3 FebMarch: 3.99 in precipitation, 1.7 in snowfall 4.0❄2 MarApril: 5.25 in precipitation 5.3 AprMay: 4.90 in precipitation 4.9 MayJune: 4.97 in precipitation 5.0 JunJuly: 4.42 in precipitation 4.4 JulAugust: 3.35 in precipitation 3.4 AugSeptember: 3.50 in precipitation 3.5 SepOctober: 3.72 in precipitation 3.7 OctNovember: 3.91 in precipitation, 0.2 in snowfall 3.9 NovDecember: 2.95 in precipitation, 3.7 in snowfall 3.0❄4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Fairfield Radio Wfiw, IL (7 mi away); precipitation: Cisne 2 S, IL (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

628236b
Cisne, IL · 4 mi
628376b
Fairfield, IL · 7 mi
628786b
Rinard, IL · 9 mi
628866b
Sims, IL · 10 mi
624466b
Mount Erie, IL · 10 mi
628506b
Johnsonville, IL · 11 mi
628436b
Golden Gate, IL · 12 mi
628096b
Barnhill, IL · 13 mi

Illinois planting zones →

Questions about 62842

What planting zone is ZIP code 62842?

ZIP code 62842 (Geff, 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 Geff, IL?

The median last spring frost (32 °F) near 62842 is April 7; after April 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Fairfield Radio Wfiw station.

When is the first frost in Geff, IL?

The median first fall frost near 62842 is October 26, giving a median frost-free growing season of 201 days.

When should I plant tomatoes in 62842?

Start tomato seeds indoors around Feb 10 – Feb 24 and set transplants outside around Apr 14 – Apr 28, one to three weeks after the median last frost.

How much rain and snow does 62842 get?

About 47 inches of precipitation a year and 12 inches of snowfall (NOAA 1991–2020 normals, Cisne 2 S station).

How hot do summers get in Geff, IL?

The average high peaks at 90 °F in July, with about 44 days a year at 90 °F or more.

What kind of soil does 62842 have?

The USDA soil survey maps Passport at the center of ZIP 62842: silt loam, somewhat poorly drained, pH about 7.0 (neutral).

Did spring come early in Geff, IL in 2026?

Spring leaf-out near 62842 came on Mar 6 in 2026, 9 days earlier than the 1991–2020 average (Mar 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Geff, IL?

Intermediate onions: the longest day near 62842 is 14 h 51 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 62842 change?

Yes. The 2012 USDA map put 62842 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.