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

Planting zone for 62249 — Highland, IL

ZIP code 62249 (Highland, Madison County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 6 and the first fall frost October 29.

Where ZIP 62249 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.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostApr 6
First frostOct 29
2012 zone6a

Was 6a 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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Highland, 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 Highland, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 6median — 50% chance of a later frost
Safe for tender plantsApril 22only 10% chance of frost after
First fall frostOctober 29median — 10% chance by Oct 16
Growing season204 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 28 and returns around November 8.

From the NOAA station Carlyle Rsvr, IL — 19 miles away, elevation 502 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 62249

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 23 – Mar 9
SpinachSow outdoors · Feb 23 – Mar 16
Broccoli, cabbageStart indoors · Jan 26 – Feb 9
Broccoli, cabbageTransplant · Mar 16 – Mar 30
Onion setsPlant outdoors · Mar 9 – Mar 23
PotatoesPlant outdoors · Mar 16 – Mar 30
LettuceSow outdoors · Mar 9 – Mar 23
Carrots, beetsSow outdoors · Mar 16 – Mar 30
TomatoesStart indoors · Feb 9 – Feb 23
TomatoesTransplant · Apr 13 – Apr 27
Peppers, eggplantStart indoors · Jan 26 – Feb 9
Peppers, eggplantTransplant · Apr 20 – May 4
BeansSow outdoors · Apr 13 – Apr 27
Sweet cornSow outdoors · Apr 13 – Apr 27
Cucumbers, squashSow outdoors · Apr 13 – Apr 27
Fall lettuce, spinachSow outdoors · Sep 3 – Sep 17
GarlicPlant cloves · Oct 15 – Nov 19
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 6) and first fall frost (Oct 29) 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 62249 came on Mar 3 — 15 days earlier than the 1991–2020 average (Mar 18).

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 6b in Illinois

620 plants native to the lower 48 states, recorded in Illinois, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. Each links to its USDA PLANTS profile.

Trees 80

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 108

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 222

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 182

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °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 °F

Vines 11

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °Fheartleaf peppervine2 ft · blooms late spring · low shade tolerance · to −8 °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 Highland, IL.

Soil in Highland, IL

The soil mapped at the center of ZIP 62249 is Coulterville — silty clay loam, somewhat poorly drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH6.7neutral; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter0.75%low — add compost
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Coulterville-Grantfork silty clay loams, 5 to 10 percent slopes, severely eroded.

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 62249; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Highland, IL

Summer high88 °Faverage high, July
Winter low22 °Faverage low, January
Hot days32days a year at 90 °F or more
Freezing nights101nights a year at 32 °F or less
Growing degree days4,186base 50 °F — the season’s usable heat
Longest day14 h 53 mindaylight on June 21
Shortest day9 h 27 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation44.5 inper year, rain and melted snow
Snowfall10 inper year; 12 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 39 °F, low 22 °F 39°22° JanFebruary: average high 45 °F, low 25 °F 45°25° FebMarch: average high 55 °F, low 35 °F 55°35° MarApril: average high 67 °F, low 45 °F 67°45° AprMay: average high 76 °F, low 56 °F 76°56° MayJune: average high 85 °F, low 65 °F 85°65° JunJuly: average high 88 °F, low 68 °F 88°68° JulAugust: average high 87 °F, low 66 °F 87°66° AugSeptember: average high 81 °F, low 58 °F 81°58° SepOctober: average high 70 °F, low 46 °F 70°46° OctNovember: average high 55 °F, low 36 °F 55°36° NovDecember: average high 43 °F, low 26 °F 43°26° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 2.74 in precipitation, 3.9 in snowfall 2.7❄4 JanFebruary: 2.45 in precipitation, 2 in snowfall 2.5❄2 FebMarch: 3.42 in precipitation, 1 in snowfall 3.4❄1 MarApril: 4.95 in precipitation 5.0 AprMay: 5.18 in precipitation 5.2 MayJune: 4.50 in precipitation 4.5 JunJuly: 4.36 in precipitation 4.4 JulAugust: 3.81 in precipitation 3.8 AugSeptember: 3.34 in precipitation 3.3 SepOctober: 3.39 in precipitation 3.4 OctNovember: 3.64 in precipitation, 0.4 in snowfall 3.6 NovDecember: 2.76 in precipitation, 2.9 in snowfall 2.8❄3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Carlyle Rsvr, IL (19 mi away); precipitation: Highland, IL (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

622736b
Pierron, IL · 5 mi
620616b
Marine, IL · 6 mi
622817a
Saint Jacob, IL · 7 mi
622756b
Pocahontas, IL · 8 mi
622166b
Aviston, IL · 9 mi
620016b
Alhambra, IL · 10 mi
622936b
Trenton, IL · 10 mi
622306b
Breese, IL · 11 mi

Illinois planting zones →

Questions about 62249

What planting zone is ZIP code 62249?

ZIP code 62249 (Highland, IL) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Highland, IL?

The median last spring frost (32 °F) near 62249 is April 6; after April 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Carlyle Rsvr station.

When is the first frost in Highland, IL?

The median first fall frost near 62249 is October 29, giving a median frost-free growing season of 204 days.

When should I plant tomatoes in 62249?

Start tomato seeds indoors around Feb 9 – Feb 23 and set transplants outside around Apr 13 – Apr 27, one to three weeks after the median last frost.

How much rain and snow does 62249 get?

About 44.5 inches of precipitation a year and 10 inches of snowfall (NOAA 1991–2020 normals, Highland station).

How hot do summers get in Highland, IL?

The average high peaks at 88 °F in July, with about 32 days a year at 90 °F or more.

What kind of soil does 62249 have?

The USDA soil survey maps Coulterville at the center of ZIP 62249: silty clay loam, somewhat poorly drained, pH about 6.7 (neutral).

Did spring come early in Highland, IL in 2026?

Spring leaf-out near 62249 came on Mar 3 in 2026, 15 days earlier than the 1991–2020 average (Mar 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Highland, IL?

Intermediate onions: the longest day near 62249 is 14 h 53 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 62249 change?

Yes. The 2012 USDA map put 62249 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.