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

Planting zone for Springfield, IL

Springfield, IL is in USDA zone 6a across its 35 ZIP codes. The median last spring frost is April 15 and the first fall frost October 22.

Springfield on the zone map

Outlined: its 8 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.

Zone6a−10 to −5 °F
ZIP codes35
Last frostApr 15
First frostOct 22
Growing season188 days

6a 35 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 Springfield, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 15median — 50% chance of a later frost
Safe for tender plantsApril 30only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 9
Growing season188 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around November 1.

From the NOAA station Springfield #2, IL, elevation 600 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 Springfield

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 4 – Mar 18
SpinachSow outdoors · Mar 4 – Mar 25
Broccoli, cabbageStart indoors · Feb 4 – Feb 18
Broccoli, cabbageTransplant · Mar 25 – Apr 8
Onion setsPlant outdoors · Mar 18 – Apr 1
PotatoesPlant outdoors · Mar 25 – Apr 8
LettuceSow outdoors · Mar 18 – Apr 1
Carrots, beetsSow outdoors · Mar 25 – Apr 8
TomatoesStart indoors · Feb 18 – Mar 4
TomatoesTransplant · Apr 22 – May 6
Peppers, eggplantStart indoors · Feb 4 – Feb 18
Peppers, eggplantTransplant · Apr 29 – May 13
BeansSow outdoors · Apr 22 – May 6
Sweet cornSow outdoors · Apr 22 – May 6
Cucumbers, squashSow outdoors · Apr 22 – May 6
Fall lettuce, spinachSow outdoors · Aug 27 – Sep 10
GarlicPlant cloves · Oct 8 – Nov 12
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 15) and first fall frost (Oct 22) 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 62703 came on Mar 11 — 14 days earlier than the 1991–2020 average (Mar 25).

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.

Trees 78

Shrubs 108

Wildflowers & perennials 220

Grasses 178

Vines 9

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 Springfield, IL.

Soil in Springfield, IL

The soil mapped at the center of ZIP 62703 is Sable — silty clay loam, poorly drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH6.0slightly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter4.5%moderate
Hydrologic groupB/Dmoderate when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Sable silty clay 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 62703; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Springfield, IL

Summer high86 °Faverage high, July
Winter low19 °Faverage low, January
Hot days23days a year at 90 °F or more
Freezing nights114nights a year at 32 °F or less
Growing degree days3,608base 50 °F — the season’s usable heat
Longest day14 h 59 mindaylight on June 21
Shortest day9 h 21 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation37.4 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 36 °F, low 19 °F 36°19° JanFebruary: average high 41 °F, low 22 °F 41°22° FebMarch: average high 52 °F, low 31 °F 52°31° MarApril: average high 65 °F, low 41 °F 65°41° AprMay: average high 74 °F, low 53 °F 74°53° MayJune: average high 83 °F, low 63 °F 83°63° JunJuly: average high 86 °F, low 66 °F 86°66° JulAugust: average high 84 °F, low 64 °F 84°64° AugSeptember: average high 78 °F, low 56 °F 78°56° SepOctober: average high 66 °F, low 44 °F 66°44° OctNovember: average high 53 °F, low 33 °F 53°33° NovDecember: average high 41 °F, low 24 °F 41°24° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.02 in precipitation 2.0 JanFebruary: 2.11 in precipitation 2.1 FebMarch: 2.60 in precipitation 2.6 MarApril: 3.91 in precipitation 3.9 AprMay: 4.54 in precipitation 4.5 MayJune: 4.52 in precipitation 4.5 JunJuly: 3.69 in precipitation 3.7 JulAugust: 2.95 in precipitation 3.0 AugSeptember: 3.00 in precipitation 3.0 SepOctober: 3.13 in precipitation 3.1 OctNovember: 2.85 in precipitation 2.9 NovDecember: 2.12 in precipitation 2.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Springfield #2, IL (3 mi away); precipitation: Lake Springfield, IL (within 1 mile). Daylight is calculated from latitude.

ZIP codes in Springfield

Illinois planting zones →

Questions about Springfield

What planting zone is Springfield, IL?

Springfield, IL is in USDA hardiness zone 6a on the 2023 map (6a: −10 to −5 °F).

When is the last frost in Springfield, IL?

The median last spring frost is April 15 and the median first fall frost is October 22 (NOAA 1991–2020 normals, Springfield #2 station).

When can I plant a garden in Springfield, IL?

Cool-season crops like peas and spinach go in around Mar 4 – Mar 25; tomatoes, peppers, beans and squash after about Apr 22, once frost risk has passed.

What kind of onions grow in Springfield, IL?

Intermediate onions: the longest day is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Springfield, IL get?

About 37.4 inches of precipitation a year (NOAA 1991–2020 normals).