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

Planting zone for Oak Lawn, IL

Oak Lawn, IL is in USDA zone 6a across its 2 ZIP codes. The median last spring frost is April 10 and the first fall frost November 1.

Oak Lawn on the zone map

Outlined: its 1 ZIP code areas · 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
ZIP codes2
Last frostApr 10
First frostNov 1
Growing season203 days

6a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 Oak Lawn, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 10median — 50% chance of a later frost
Safe for tender plantsApril 26only 10% chance of frost after
First fall frostNovember 1median — 10% chance by Oct 21
Growing season203 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 1 and returns around November 11.

From the NOAA station Chicago Midway Airport 3sw, IL, elevation 620 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 Oak Lawn

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 27 – Mar 13
SpinachSow outdoors · Feb 27 – Mar 20
Broccoli, cabbageStart indoors · Jan 30 – Feb 13
Broccoli, cabbageTransplant · Mar 20 – Apr 3
Onion setsPlant outdoors · Mar 13 – Mar 27
PotatoesPlant outdoors · Mar 20 – Apr 3
LettuceSow outdoors · Mar 13 – Mar 27
Carrots, beetsSow outdoors · Mar 20 – Apr 3
TomatoesStart indoors · Feb 13 – Feb 27
TomatoesTransplant · Apr 17 – May 1
Peppers, eggplantStart indoors · Jan 30 – Feb 13
Peppers, eggplantTransplant · Apr 24 – May 8
BeansSow outdoors · Apr 17 – May 1
Sweet cornSow outdoors · Apr 17 – May 1
Cucumbers, squashSow outdoors · Apr 17 – May 1
Fall lettuce, spinachSow outdoors · Sep 6 – Sep 20
GarlicPlant cloves · Oct 18 – Nov 22
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 10) and first fall frost (Nov 1) 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 60454 came on Mar 21 — 13 days earlier than the 1991–2020 average (Apr 3).

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.

Trees 78

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 108

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 220

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 178

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °F

Vines 9

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °F

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 Oak Lawn, IL.

Soil in Oak Lawn, IL

The soil mapped at the center of ZIP 60454 is Orthents — silty clay, moderately well drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureSilty clayholds water and nutrients; slow to drain and warm up
pH6.7neutral; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter1.25%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land.

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 60454; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Oak Lawn, IL

Summer high85 °Faverage high, July
Winter low19 °Faverage low, January
Hot days20days a year at 90 °F or more
Freezing nights106nights a year at 32 °F or less
Growing degree days3,526base 50 °F — the season’s usable heat
Longest day15 h 13 mindaylight on June 21
Shortest day9 h 08 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation34.4 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 33 °F, low 19 °F 33°19° JanFebruary: average high 37 °F, low 23 °F 37°23° FebMarch: average high 48 °F, low 32 °F 48°32° MarApril: average high 60 °F, low 41 °F 60°41° AprMay: average high 71 °F, low 52 °F 71°52° MayJune: average high 81 °F, low 62 °F 81°62° JunJuly: average high 85 °F, low 68 °F 85°68° JulAugust: average high 83 °F, low 66 °F 83°66° AugSeptember: average high 76 °F, low 59 °F 76°59° SepOctober: average high 63 °F, low 47 °F 63°47° OctNovember: average high 49 °F, low 35 °F 49°35° NovDecember: average high 38 °F, low 25 °F 38°25° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 1.48 in precipitation 1.5 JanFebruary: 1.46 in precipitation 1.5 FebMarch: 1.88 in precipitation 1.9 MarApril: 3.57 in precipitation 3.6 AprMay: 4.09 in precipitation 4.1 MayJune: 4.01 in precipitation 4.0 JunJuly: 3.55 in precipitation 3.5 JulAugust: 3.99 in precipitation 4.0 AugSeptember: 2.77 in precipitation 2.8 SepOctober: 3.48 in precipitation 3.5 OctNovember: 2.35 in precipitation 2.4 NovDecember: 1.79 in precipitation 1.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Chicago Midway Airport, IL (4 mi away); precipitation: Chicago Midway Airport, IL (4 mi away). Daylight is calculated from latitude.

ZIP codes in Oak Lawn

604536a
−10 to −5 °F
604546a
−10 to −5 °F

Illinois planting zones →

Questions about Oak Lawn

What planting zone is Oak Lawn, IL?

Oak Lawn, IL is in USDA hardiness zone 6a on the 2023 map (6a: −10 to −5 °F).

When is the last frost in Oak Lawn, IL?

The median last spring frost is April 10 and the median first fall frost is November 1 (NOAA 1991–2020 normals, Chicago Midway Airport 3sw station).

When can I plant a garden in Oak Lawn, IL?

Cool-season crops like peas and spinach go in around Feb 27 – Mar 20; tomatoes, peppers, beans and squash after about Apr 17, once frost risk has passed.

What kind of onions grow in Oak Lawn, IL?

Long-day onions: the longest day is 15 h 13 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Oak Lawn, IL get?

About 34.4 inches of precipitation a year (NOAA 1991–2020 normals).