Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 61854 — Mansfield, IL

ZIP code 61854 (Mansfield, Piatt County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 23 and the first fall frost October 13.

Where ZIP 61854 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.

Zone6a−10 to −5 °F

Coldest night−23.3 to −20.6 °C

Last frostApr 23

First frostOct 13

2012 zone5b

Was 5b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Mansfield, 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 Mansfield, IL

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 23median — 50% chance of a later frost

Safe for tender plantsMay 9only 10% chance of frost after

First fall frostOctober 13median — 10% chance by Sep 28

Growing season170 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 11 and returns around October 23.

From the NOAA station Champaign 9 Sw, IL — 13 miles away, elevation 699 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 61854

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 12 – Mar 26

SpinachSow outdoors · Mar 12 – Apr 2

Broccoli, cabbageStart indoors · Feb 12 – Feb 26

Broccoli, cabbageTransplant · Apr 2 – Apr 16

Onion setsPlant outdoors · Mar 26 – Apr 9

PotatoesPlant outdoors · Apr 2 – Apr 16

LettuceSow outdoors · Mar 26 – Apr 9

Carrots, beetsSow outdoors · Apr 2 – Apr 16

TomatoesStart indoors · Feb 26 – Mar 12

TomatoesTransplant · Apr 30 – May 14

Peppers, eggplantStart indoors · Feb 12 – Feb 26

Peppers, eggplantTransplant · May 7 – May 21

BeansSow outdoors · Apr 30 – May 14

Sweet cornSow outdoors · Apr 30 – May 14

Cucumbers, squashSow outdoors · Apr 30 – May 14

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 23) 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 61854 came on Mar 11 — 19 days earlier than the 1991–2020 average (Mar 30).

average
Mar 302026
Mar 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 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.

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 Mansfield, IL.

Soil in Mansfield, IL

The soil mapped at the center of ZIP 61854 is Ipava — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables

pH5.8moderately acidic; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter4.25%moderate

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classprime farmlandUSDA classification

Map unit: Ipava silt loam, 0 to 2 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 61854; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mansfield, IL

Summer high84 °Faverage high, July

Winter low17 °Faverage low, January

Hot days15days a year at 90 °F or more

Freezing nights128nights a year at 32 °F or less

Growing degree days3,208base 50 °F — the season’s usable heat

Longest day15 h 02 mindaylight on June 21

Shortest day9 h 18 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation39.6 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Champaign 9 Sw, IL (13 mi away); precipitation: Mansfield 3.0 Wsw, IL (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

Farmer City, IL · 8 mi

618846a

White Heath, IL · 8 mi

618756a

Seymour, IL · 9 mi

617246a

Bellflower, IL · 9 mi

618266a

Champaign, IL · 11 mi

618436a

Fisher, IL · 12 mi

Illinois planting zones →

Questions about 61854

What planting zone is ZIP code 61854?

ZIP code 61854 (Mansfield, IL) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Mansfield, IL?

The median last spring frost (32 °F) near 61854 is April 23; after May 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Champaign 9 Sw station.

When is the first frost in Mansfield, IL?

The median first fall frost near 61854 is October 13, giving a median frost-free growing season of 170 days.

When should I plant tomatoes in 61854?

Start tomato seeds indoors around Feb 26 – Mar 12 and set transplants outside around Apr 30 – May 14, one to three weeks after the median last frost.

How much rain and snow does 61854 get?

About 39.6 inches of precipitation a year (NOAA 1991–2020 normals, Mansfield 3.0 Wsw station).

How hot do summers get in Mansfield, IL?

The average high peaks at 84 °F in July, with about 15 days a year at 90 °F or more.

What kind of soil does 61854 have?

The USDA soil survey maps Ipava at the center of ZIP 61854: silt loam, somewhat poorly drained, pH about 5.8 (moderately acidic).

Did spring come early in Mansfield, IL in 2026?

Spring leaf-out near 61854 came on Mar 11 in 2026, 19 days earlier than the 1991–2020 average (Mar 30), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mansfield, IL?

Long-day onions: the longest day near 61854 is 15 h 02 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 61854 change?

Yes. The 2012 USDA map put 61854 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.