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

Planting zone for 61957 — Windsor, IL

ZIP code 61957 (Windsor, Shelby County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 16 and the first fall frost October 22.

Where ZIP 61957 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 16
First frostOct 22
2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Windsor, 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 Windsor, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 16median — 50% chance of a later frost
Safe for tender plantsApril 30only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 8
Growing season187 daysfrost-free, median

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

From the NOAA station Windsor, IL — within 1 mile, elevation 689 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 61957

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 5 – Mar 19
SpinachSow outdoors · Mar 5 – Mar 26
Broccoli, cabbageStart indoors · Feb 5 – Feb 19
Broccoli, cabbageTransplant · Mar 26 – Apr 9
Onion setsPlant outdoors · Mar 19 – Apr 2
PotatoesPlant outdoors · Mar 26 – Apr 9
LettuceSow outdoors · Mar 19 – Apr 2
Carrots, beetsSow outdoors · Mar 26 – Apr 9
TomatoesStart indoors · Feb 19 – Mar 5
TomatoesTransplant · Apr 23 – May 7
Peppers, eggplantStart indoors · Feb 5 – Feb 19
Peppers, eggplantTransplant · Apr 30 – May 14
BeansSow outdoors · Apr 23 – May 7
Sweet cornSow outdoors · Apr 23 – May 7
Cucumbers, squashSow outdoors · Apr 23 – May 7
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 16) 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 61957 came on Mar 10 — 13 days earlier than the 1991–2020 average (Mar 23).

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 Windsor, IL.

Soil in Windsor, IL

The soil mapped at the center of ZIP 61957 is Flanagan — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter4.5%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Flanagan silt loam.

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 61957; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Windsor, IL

Summer high85 °Faverage high, July
Winter low19 °Faverage low, January
Hot days26days a year at 90 °F or more
Freezing nights109nights a year at 32 °F or less
Growing degree days3,553base 50 °F — the season’s usable heat
Longest day14 h 57 mindaylight on June 21
Shortest day9 h 23 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation41.2 inper year, rain and melted snow
Snowfall14 inper year; 21 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 35 °F, low 19 °F 35°19° JanFebruary: average high 40 °F, low 23 °F 40°23° FebMarch: average high 51 °F, low 32 °F 51°32° MarApril: average high 64 °F, low 42 °F 64°42° AprMay: average high 74 °F, low 53 °F 74°53° MayJune: average high 82 °F, low 62 °F 82°62° JunJuly: average high 85 °F, low 65 °F 85°65° JulAugust: average high 84 °F, low 63 °F 84°63° AugSeptember: average high 78 °F, low 55 °F 78°55° SepOctober: average high 66 °F, low 44 °F 66°44° OctNovember: average high 51 °F, low 33 °F 51°33° NovDecember: average high 39 °F, low 25 °F 39°25° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 2.64 in precipitation, 5.2 in snowfall 2.6❄5 JanFebruary: 1.97 in precipitation, 3.4 in snowfall 2.0❄3 FebMarch: 3.11 in precipitation, 1.4 in snowfall 3.1❄1 MarApril: 4.51 in precipitation, 0.3 in snowfall 4.5 AprMay: 4.57 in precipitation 4.6 MayJune: 4.76 in precipitation 4.8 JunJuly: 3.91 in precipitation 3.9 JulAugust: 2.95 in precipitation 3.0 AugSeptember: 2.97 in precipitation 3.0 SepOctober: 3.60 in precipitation 3.6 OctNovember: 3.75 in precipitation, 0.8 in snowfall 3.8❄1 NovDecember: 2.45 in precipitation, 2.6 in snowfall 2.5❄3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Windsor, IL (within 1 mile); precipitation: Windsor, IL (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

Illinois planting zones →

Questions about 61957

What planting zone is ZIP code 61957?

ZIP code 61957 (Windsor, 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 Windsor, IL?

The median last spring frost (32 °F) near 61957 is April 16; after April 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Windsor station.

When is the first frost in Windsor, IL?

The median first fall frost near 61957 is October 22, giving a median frost-free growing season of 187 days.

When should I plant tomatoes in 61957?

Start tomato seeds indoors around Feb 19 – Mar 5 and set transplants outside around Apr 23 – May 7, one to three weeks after the median last frost.

How much rain and snow does 61957 get?

About 41.2 inches of precipitation a year and 14 inches of snowfall (NOAA 1991–2020 normals, Windsor station).

How hot do summers get in Windsor, IL?

The average high peaks at 85 °F in July, with about 26 days a year at 90 °F or more.

What kind of soil does 61957 have?

The USDA soil survey maps Flanagan at the center of ZIP 61957: silt loam, somewhat poorly drained, pH about 6.2 (slightly acidic).

Did spring come early in Windsor, IL in 2026?

Spring leaf-out near 61957 came on Mar 10 in 2026, 13 days earlier than the 1991–2020 average (Mar 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Windsor, IL?

Intermediate onions: the longest day near 61957 is 14 h 57 min, so day-neutral types bulb best; long-day varieties may not bulb fully.