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

Planting zone for 61378 — West Brooklyn, IL

ZIP code 61378 (West Brooklyn, 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 61378 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 zone5b

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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for West Brooklyn, 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 West Brooklyn, 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 — 3 miles away, 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 61378

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 61378 came on Mar 25 — 13 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

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 102

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 210

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 173

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 West Brooklyn, IL.

Soil in West Brooklyn, IL

The soil mapped at the center of ZIP 61378 is Catlin — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH7.0neutral; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter3.5%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Catlin silt loam, Illinois till plain, 2 to 5 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 61378; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in West Brooklyn, 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 13 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)
Precipitation35.1 inper year, rain and melted snow
Snowfall28 inper year; 44 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 28 °F, low 12 °F 28°12° JanFebruary: average high 33 °F, low 16 °F 33°16° FebMarch: average high 46 °F, low 26 °F 46°26° MarApril: average high 59 °F, low 36 °F 59°36° AprMay: average high 71 °F, low 49 °F 71°49° MayJune: average high 80 °F, low 58 °F 80°58° JunJuly: average high 83 °F, low 61 °F 83°61° JulAugust: average high 81 °F, low 60 °F 81°60° AugSeptember: average high 75 °F, low 51 °F 75°51° SepOctober: average high 63 °F, low 40 °F 63°40° OctNovember: average high 47 °F, low 29 °F 47°29° NovDecember: average high 34 °F, low 19 °F 34°19° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 1.49 in precipitation, 8.6 in snowfall 1.5❄9 JanFebruary: 1.41 in precipitation, 8.8 in snowfall 1.4❄9 FebMarch: 2.13 in precipitation, 1.9 in snowfall 2.1❄2 MarApril: 3.40 in precipitation, 0.6 in snowfall 3.4❄1 AprMay: 4.58 in precipitation 4.6 MayJune: 4.50 in precipitation 4.5 JunJuly: 3.93 in precipitation 3.9 JulAugust: 3.84 in precipitation 3.8 AugSeptember: 3.47 in precipitation 3.5 SepOctober: 2.76 in precipitation 2.8 OctNovember: 1.77 in precipitation, 1.5 in snowfall 1.8❄2 NovDecember: 1.80 in precipitation, 6.9 in snowfall 1.8❄7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Compton 1 Nw, IL (3 mi away); precipitation: Steward 3s, IL (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

613185b
Compton, IL · 4 mi
613315b
Lee Center, IL · 7 mi
613535b
Paw Paw, IL · 9 mi
613675b
Sublette, IL · 9 mi
605535b
Steward, IL · 9 mi
610065b
Ashton, IL · 10 mi
613105b
Amboy, IL · 10 mi
610315b
Franklin Grove, IL · 11 mi

Illinois planting zones →

Questions about 61378

What planting zone is ZIP code 61378?

ZIP code 61378 (West Brooklyn, 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 West Brooklyn, IL?

The median last spring frost (32 °F) near 61378 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 West Brooklyn, IL?

The median first fall frost near 61378 is October 12, giving a median frost-free growing season of 167 days.

When should I plant tomatoes in 61378?

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 61378 get?

About 35.1 inches of precipitation a year and 28 inches of snowfall (NOAA 1991–2020 normals, Steward 3s station).

How hot do summers get in West Brooklyn, 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 61378 have?

The USDA soil survey maps Catlin at the center of ZIP 61378: silt loam, moderately well drained, pH about 7.0 (neutral).

Did spring come early in West Brooklyn, IL in 2026?

Spring leaf-out near 61378 came on Mar 25 in 2026, 13 days earlier than the 1991–2020 average (Apr 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in West Brooklyn, IL?

Long-day onions: the longest day near 61378 is 15 h 13 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).