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

Planting zone for 61027 — Eleroy, IL

ZIP code 61027 (Eleroy, Stephenson County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 26 and the first fall frost October 13.

Where ZIP 61027 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostApr 26
First frostOct 13
2012 zone5a

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Eleroy, 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 Eleroy, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 26median — 50% chance of a later frost
Safe for tender plantsMay 11only 10% chance of frost after
First fall frostOctober 13median — 10% chance by Sep 30
Growing season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 14 and returns around October 24.

From the NOAA station Freeport Waste Wtp, IL — 8 miles away, elevation 751 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 61027

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 15 – Mar 29
SpinachSow outdoors · Mar 15 – Apr 5
Broccoli, cabbageStart indoors · Feb 15 – Mar 1
Broccoli, cabbageTransplant · Apr 5 – Apr 19
Onion setsPlant outdoors · Mar 29 – Apr 12
PotatoesPlant outdoors · Apr 5 – Apr 19
LettuceSow outdoors · Mar 29 – Apr 12
Carrots, beetsSow outdoors · Apr 5 – Apr 19
TomatoesStart indoors · Mar 1 – Mar 15
TomatoesTransplant · May 3 – May 17
Peppers, eggplantStart indoors · Feb 15 – Mar 1
Peppers, eggplantTransplant · May 10 – May 24
BeansSow outdoors · May 3 – May 17
Sweet cornSow outdoors · May 3 – May 17
Cucumbers, squashSow outdoors · May 3 – May 17
Fall lettuce, spinachSow outdoors · Aug 18 – Sep 1
GarlicPlant cloves · Sep 29 – Nov 3
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 26) and first fall frost (Oct 13) 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 61027 came on Mar 28 — 14 days earlier than the 1991–2020 average (Apr 11).

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 5a in Illinois

550 plants native to the lower 48 states, recorded in Illinois, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 65

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 95

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 202

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 167

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 7

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °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 °Ftrumpet honeysuckle16 ft · blooms late summer · low shade tolerance · to −33 °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 Eleroy, IL.

Soil in Eleroy, IL

The soil mapped at the center of ZIP 61027 is Radford — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH6.7neutral; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter3%moderate
Hydrologic groupB/Dmoderate when drained; wet otherwise
Farmland classprime farmlandUSDA classification

Map unit: Radford silt loam, 0 to 2 percent slopes, occasionally flooded.

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 61027; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Eleroy, IL

Summer high82 °Faverage high, July
Winter low11 °Faverage low, January
Hot days11days a year at 90 °F or more
Freezing nights148nights a year at 32 °F or less
Growing degree days2,811base 50 °F — the season’s usable heat
Longest day15 h 17 mindaylight on June 21
Shortest day9 h 05 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation38.8 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 28 °F, low 11 °F 28°11° JanFebruary: average high 33 °F, low 15 °F 33°15° FebMarch: average high 45 °F, low 26 °F 45°26° MarApril: average high 58 °F, low 36 °F 58°36° AprMay: average high 70 °F, low 48 °F 70°48° MayJune: average high 79 °F, low 59 °F 79°59° JunJuly: average high 82 °F, low 62 °F 82°62° JulAugust: average high 81 °F, low 60 °F 81°60° AugSeptember: average high 74 °F, low 51 °F 74°51° SepOctober: average high 62 °F, low 39 °F 62°39° OctNovember: average high 46 °F, low 28 °F 46°28° NovDecember: average high 33 °F, low 18 °F 33°18° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 1.53 in precipitation 1.5 JanFebruary: 1.69 in precipitation 1.7 FebMarch: 2.27 in precipitation 2.3 MarApril: 3.74 in precipitation 3.7 AprMay: 4.49 in precipitation 4.5 MayJune: 5.43 in precipitation 5.4 JunJuly: 4.39 in precipitation 4.4 JulAugust: 4.12 in precipitation 4.1 AugSeptember: 3.85 in precipitation 3.9 SepOctober: 3.01 in precipitation 3.0 OctNovember: 2.37 in precipitation 2.4 NovDecember: 1.92 in precipitation 1.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Freeport Waste Wtp, IL (8 mi away); precipitation: Freeport 2.0 Nw, IL (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

610485a
Lena, IL · 6 mi
610325a
Freeport, IL · 6 mi
610135a
Cedarville, IL · 7 mi
610625a
Pearl City, IL · 7 mi
610505a
Mc Connell, IL · 7 mi
610445a
Kent, IL · 8 mi
610895a
Winslow, IL · 10 mi
610785a
Shannon, IL · 12 mi

Illinois planting zones →

Questions about 61027

What planting zone is ZIP code 61027?

ZIP code 61027 (Eleroy, IL) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Eleroy, IL?

The median last spring frost (32 °F) near 61027 is April 26; after May 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Freeport Waste Wtp station.

When is the first frost in Eleroy, IL?

The median first fall frost near 61027 is October 13, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 61027?

Start tomato seeds indoors around Mar 1 – Mar 15 and set transplants outside around May 3 – May 17, one to three weeks after the median last frost.

How much rain and snow does 61027 get?

About 38.8 inches of precipitation a year (NOAA 1991–2020 normals, Freeport 2.0 Nw station).

How hot do summers get in Eleroy, IL?

The average high peaks at 82 °F in July, with about 11 days a year at 90 °F or more.

What kind of soil does 61027 have?

The USDA soil survey maps Radford at the center of ZIP 61027: silt loam, somewhat poorly drained, pH about 6.7 (neutral).

Did spring come early in Eleroy, IL in 2026?

Spring leaf-out near 61027 came on Mar 28 in 2026, 14 days earlier than the 1991–2020 average (Apr 11), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Eleroy, IL?

Long-day onions: the longest day near 61027 is 15 h 17 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).