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

Planting zone for 61051 — Milledgeville, IL

ZIP code 61051 (Milledgeville, Carroll County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 29 and the first fall frost October 7.

Where ZIP 61051 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 29
First frostOct 7
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 Milledgeville, 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 Milledgeville, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 29median — 50% chance of a later frost
Safe for tender plantsMay 14only 10% chance of frost after
First fall frostOctober 7median — 10% chance by Sep 23
Growing season161 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 19 and returns around October 19.

From the NOAA station Polo 5nw, IL — 9 miles away, elevation 856 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 61051

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 18 – Apr 1
SpinachSow outdoors · Mar 18 – Apr 8
Broccoli, cabbageStart indoors · Feb 18 – Mar 4
Broccoli, cabbageTransplant · Apr 8 – Apr 22
Onion setsPlant outdoors · Apr 1 – Apr 15
PotatoesPlant outdoors · Apr 8 – Apr 22
LettuceSow outdoors · Apr 1 – Apr 15
Carrots, beetsSow outdoors · Apr 8 – Apr 22
TomatoesStart indoors · Mar 4 – Mar 18
TomatoesTransplant · May 6 – May 20
Peppers, eggplantStart indoors · Feb 18 – Mar 4
Peppers, eggplantTransplant · May 13 – May 27
BeansSow outdoors · May 6 – May 20
Sweet cornSow outdoors · May 6 – May 20
Cucumbers, squashSow outdoors · May 6 – May 20
Fall lettuce, spinachSow outdoors · Aug 12 – Aug 26
GarlicPlant cloves · Sep 23 – Oct 28
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 29) and first fall frost (Oct 7) 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 61051 came on Mar 25 — 14 days earlier than the 1991–2020 average (Apr 8).

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 Milledgeville, IL.

Soil in Milledgeville, IL

The soil mapped at the center of ZIP 61051 is Osco — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH6.0slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3.5%moderate
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: Osco silt loam, 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 61051; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Milledgeville, IL

Summer high85 °Faverage high, July
Winter low13 °Faverage low, January
Hot days17days a year at 90 °F or more
Freezing nights138nights a year at 32 °F or less
Growing degree days3,067base 50 °F — the season’s usable heat
Longest day15 h 14 mindaylight on June 21
Shortest day9 h 07 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

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 30 °F, low 13 °F 30°13° JanFebruary: average high 35 °F, low 17 °F 35°17° FebMarch: average high 48 °F, low 28 °F 48°28° MarApril: average high 61 °F, low 38 °F 61°38° AprMay: average high 73 °F, low 49 °F 73°49° MayJune: average high 82 °F, low 59 °F 82°59° JunJuly: average high 85 °F, low 62 °F 85°62° JulAugust: average high 83 °F, low 59 °F 83°59° AugSeptember: average high 77 °F, low 51 °F 77°51° SepOctober: average high 64 °F, low 40 °F 64°40° OctNovember: average high 48 °F, low 29 °F 48°29° NovDecember: average high 35 °F, low 19 °F 35°19° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 1.70 in precipitation 1.7 JanFebruary: 2.01 in precipitation 2.0 FebMarch: 2.59 in precipitation 2.6 MarApril: 3.87 in precipitation 3.9 AprMay: 4.88 in precipitation 4.9 MayJune: 5.05 in precipitation 5.0 JunJuly: 4.34 in precipitation 4.3 JulAugust: 4.12 in precipitation 4.1 AugSeptember: 3.64 in precipitation 3.6 SepOctober: 2.85 in precipitation 2.9 OctNovember: 2.40 in precipitation 2.4 NovDecember: 2.04 in precipitation 2.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Polo 5nw, IL (9 mi away); precipitation: Coleta 1.4 Ssw, IL (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

5 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

610145a
Chadwick, IL · 6 mi
610465a
Lanark, IL · 9 mi
610645b
Polo, IL · 9 mi
610815b
Sterling, IL · 9 mi
610915b
Woosung, IL · 12 mi
610785a
Shannon, IL · 13 mi
610305b
Forreston, IL · 13 mi
610375b
Galt, IL · 13 mi

Illinois planting zones →

Questions about 61051

What planting zone is ZIP code 61051?

ZIP code 61051 (Milledgeville, 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 Milledgeville, IL?

The median last spring frost (32 °F) near 61051 is April 29; after May 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Polo 5nw station.

When is the first frost in Milledgeville, IL?

The median first fall frost near 61051 is October 7, giving a median frost-free growing season of 161 days.

When should I plant tomatoes in 61051?

Start tomato seeds indoors around Mar 4 – Mar 18 and set transplants outside around May 6 – May 20, one to three weeks after the median last frost.

How much rain and snow does 61051 get?

About 39.5 inches of precipitation a year (NOAA 1991–2020 normals, Coleta 1.4 Ssw station).

How hot do summers get in Milledgeville, IL?

The average high peaks at 85 °F in July, with about 17 days a year at 90 °F or more.

What kind of soil does 61051 have?

The USDA soil survey maps Osco at the center of ZIP 61051: silt loam, well drained, pH about 6.0 (slightly acidic).

Did spring come early in Milledgeville, IL in 2026?

Spring leaf-out near 61051 came on Mar 25 in 2026, 14 days earlier than the 1991–2020 average (Apr 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Milledgeville, IL?

Long-day onions: the longest day near 61051 is 15 h 14 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).