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

Planting zone for 61318 — Compton, IL

ZIP code 61318 (Compton, Lee County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 27 and the first fall frost October 12.

Where ZIP 61318 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.

Zone5b−15 to −10 °F

Coldest night−26.1 to −23.3 °C

Last frostApr 27

First frostOct 12

2012 zone5a

Was 5a 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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Compton, 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 Compton, IL

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 27median — 50% chance of a later frost

Safe for tender plantsMay 14only 10% chance of frost after

First fall frostOctober 12median — 10% chance by Sep 27

Growing season167 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 16 and returns around October 24.

From the NOAA station Compton 1 Nw, IL — within 1 mile, elevation 906 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 61318

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 16 – Mar 30

SpinachSow outdoors · Mar 16 – Apr 6

Broccoli, cabbageStart indoors · Feb 16 – Mar 2

Broccoli, cabbageTransplant · Apr 6 – Apr 20

Onion setsPlant outdoors · Mar 30 – Apr 13

PotatoesPlant outdoors · Apr 6 – Apr 20

LettuceSow outdoors · Mar 30 – Apr 13

Carrots, beetsSow outdoors · Apr 6 – Apr 20

TomatoesStart indoors · Mar 2 – Mar 16

TomatoesTransplant · May 4 – May 18

Peppers, eggplantStart indoors · Feb 16 – Mar 2

Peppers, eggplantTransplant · May 11 – May 25

BeansSow outdoors · May 4 – May 18

Sweet cornSow outdoors · May 4 – May 18

Cucumbers, squashSow outdoors · May 4 – May 18

Fall lettuce, spinachSow outdoors · Aug 17 – Aug 31

GarlicPlant cloves · Sep 28 – Nov 2

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 27) and first fall frost (Oct 12) 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 61318 came on Mar 28 — 11 days earlier than the 1991–2020 average (Apr 8).

average
Apr 82026
Mar 28

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 5b in Illinois

584 plants native to the lower 48 states, recorded in Illinois, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. 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 Compton, IL.

Soil in Compton, IL

The soil mapped at the center of ZIP 61318 is Saybrook — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables

pH6.0slightly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter3%moderate

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Saybrook silt loam, 2 to 5 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 61318; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Compton, IL

Summer high83 °Faverage high, July

Winter low12 °Faverage low, January

Hot days14days a year at 90 °F or more

Freezing nights149nights a year at 32 °F or less

Growing degree days2,856base 50 °F — the season’s usable heat

Longest day15 h 12 mindaylight on June 21

Shortest day9 h 09 mindaylight on December 21

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

Precipitation36.8 inper year, rain and melted snow

Snowfall30 inper year; 49 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: Compton 1 Nw, IL (within 1 mile); precipitation: Paw Paw 2s, IL (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

613785b

West Brooklyn, IL · 4 mi

Lee Center, IL · 11 mi

Earlville, IL · 11 mi

Illinois planting zones →

Questions about 61318

What planting zone is ZIP code 61318?

ZIP code 61318 (Compton, IL) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Compton, IL?

The median last spring frost (32 °F) near 61318 is April 27; after May 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Compton 1 Nw station.

When is the first frost in Compton, IL?

The median first fall frost near 61318 is October 12, giving a median frost-free growing season of 167 days.

When should I plant tomatoes in 61318?

Start tomato seeds indoors around Mar 2 – Mar 16 and set transplants outside around May 4 – May 18, one to three weeks after the median last frost.

How much rain and snow does 61318 get?

About 36.8 inches of precipitation a year and 30 inches of snowfall (NOAA 1991–2020 normals, Paw Paw 2s station).

How hot do summers get in Compton, IL?

The average high peaks at 83 °F in July, with about 14 days a year at 90 °F or more.

What kind of soil does 61318 have?

The USDA soil survey maps Saybrook at the center of ZIP 61318: silt loam, moderately well drained, pH about 6.0 (slightly acidic).

Did spring come early in Compton, IL in 2026?

Spring leaf-out near 61318 came on Mar 28 in 2026, 11 days earlier than the 1991–2020 average (Apr 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Compton, IL?

Long-day onions: the longest day near 61318 is 15 h 12 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 61318 change?

Yes. The 2012 USDA map put 61318 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.