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

Planting zone for Aurora, IL

Aurora, IL is in USDA zone 5b across its 10 ZIP codes. The median last spring frost is April 19 and the first fall frost October 23.

Aurora on the zone map

Outlined: its 5 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.

Zone5b−15 to −10 °F
ZIP codes10
Last frostApr 19
First frostOct 23
Growing season185 days

5b 10 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 Aurora, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 19median — 50% chance of a later frost
Safe for tender plantsMay 4only 10% chance of frost after
First fall frostOctober 23median — 10% chance by Oct 9
Growing season185 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 8 and returns around November 2.

From the NOAA station Aurora, IL, elevation 659 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 Aurora

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 8 – Mar 22
SpinachSow outdoors · Mar 8 – Mar 29
Broccoli, cabbageStart indoors · Feb 8 – Feb 22
Broccoli, cabbageTransplant · Mar 29 – Apr 12
Onion setsPlant outdoors · Mar 22 – Apr 5
PotatoesPlant outdoors · Mar 29 – Apr 12
LettuceSow outdoors · Mar 22 – Apr 5
Carrots, beetsSow outdoors · Mar 29 – Apr 12
TomatoesStart indoors · Feb 22 – Mar 8
TomatoesTransplant · Apr 26 – May 10
Peppers, eggplantStart indoors · Feb 8 – Feb 22
Peppers, eggplantTransplant · May 3 – May 17
BeansSow outdoors · Apr 26 – May 10
Sweet cornSow outdoors · Apr 26 – May 10
Cucumbers, squashSow outdoors · Apr 26 – May 10
Fall lettuce, spinachSow outdoors · Aug 28 – Sep 11
GarlicPlant cloves · Oct 9 – Nov 13
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Oct 23) 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 60502 came on Mar 21 — 17 days earlier than the 1991–2020 average (Apr 7).

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.

Trees 77

Shrubs 102

Wildflowers & perennials 210

Grasses 173

Vines 7

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 Aurora, IL.

Soil in Aurora, IL

The soil mapped at the center of ZIP 60502 is Zurich — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH6.8neutral; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter2%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Zurich silt loam, 2 to 4 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 60502; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Aurora, IL

Summer high84 °Faverage high, July
Winter low16 °Faverage low, January
Hot days17days a year at 90 °F or more
Freezing nights134nights a year at 32 °F or less
Growing degree days3,204base 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)
Precipitation39.5 inper year, rain and melted snow
Snowfall28 inper year; 42 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 31 °F, low 16 °F 31°16° JanFebruary: average high 35 °F, low 20 °F 35°20° FebMarch: average high 47 °F, low 29 °F 47°29° MarApril: average high 60 °F, low 39 °F 60°39° AprMay: average high 71 °F, low 50 °F 71°50° MayJune: average high 81 °F, low 60 °F 81°60° JunJuly: average high 84 °F, low 65 °F 84°65° JulAugust: average high 82 °F, low 63 °F 82°63° AugSeptember: average high 76 °F, low 55 °F 76°55° SepOctober: average high 63 °F, low 43 °F 63°43° OctNovember: average high 48 °F, low 32 °F 48°32° NovDecember: average high 36 °F, low 22 °F 36°22° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 1.86 in precipitation, 9.1 in snowfall 1.9❄9 JanFebruary: 1.83 in precipitation, 7.9 in snowfall 1.8❄8 FebMarch: 2.35 in precipitation, 2.6 in snowfall 2.4❄3 MarApril: 4.05 in precipitation, 0.6 in snowfall 4.0❄1 AprMay: 4.86 in precipitation 4.9 MayJune: 4.50 in precipitation 4.5 JunJuly: 4.19 in precipitation 4.2 JulAugust: 3.86 in precipitation 3.9 AugSeptember: 3.37 in precipitation 3.4 SepOctober: 3.70 in precipitation 3.7 OctNovember: 2.71 in precipitation, 1.3 in snowfall 2.7❄1 NovDecember: 2.19 in precipitation, 6.4 in snowfall 2.2❄6 Dec

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

ZIP codes in Aurora

Illinois planting zones →

Questions about Aurora

What planting zone is Aurora, IL?

Aurora, IL is in USDA hardiness zone 5b on the 2023 map (5b: −15 to −10 °F).

When is the last frost in Aurora, IL?

The median last spring frost is April 19 and the median first fall frost is October 23 (NOAA 1991–2020 normals, Aurora station).

When can I plant a garden in Aurora, IL?

Cool-season crops like peas and spinach go in around Mar 8 – Mar 29; tomatoes, peppers, beans and squash after about Apr 26, once frost risk has passed.

What kind of onions grow in Aurora, 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 Aurora, IL get?

About 39.5 inches of precipitation a year and 28 inches of snowfall (NOAA 1991–2020 normals).