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

Planting zone for 62079 — Piasa, IL

ZIP code 62079 (Piasa, Macoupin County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 14 and the first fall frost October 19.

Where ZIP 62079 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 14
First frostOct 19
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 Piasa, 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 Piasa, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 14median — 50% chance of a later frost
Safe for tender plantsApril 30only 10% chance of frost after
First fall frostOctober 19median — 10% chance by Oct 7
Growing season187 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 4 and returns around October 30.

From the NOAA station Jerseyville 2 Sw, IL — 11 miles away, elevation 630 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 62079

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 3 – Mar 17
SpinachSow outdoors · Mar 3 – Mar 24
Broccoli, cabbageStart indoors · Feb 3 – Feb 17
Broccoli, cabbageTransplant · Mar 24 – Apr 7
Onion setsPlant outdoors · Mar 17 – Mar 31
PotatoesPlant outdoors · Mar 24 – Apr 7
LettuceSow outdoors · Mar 17 – Mar 31
Carrots, beetsSow outdoors · Mar 24 – Apr 7
TomatoesStart indoors · Feb 17 – Mar 3
TomatoesTransplant · Apr 21 – May 5
Peppers, eggplantStart indoors · Feb 3 – Feb 17
Peppers, eggplantTransplant · Apr 28 – May 12
BeansSow outdoors · Apr 21 – May 5
Sweet cornSow outdoors · Apr 21 – May 5
Cucumbers, squashSow outdoors · Apr 21 – May 5
Fall lettuce, spinachSow outdoors · Aug 24 – Sep 7
GarlicPlant cloves · Oct 5 – Nov 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 14) and first fall frost (Oct 19) 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 62079 came on Mar 8 — 12 days earlier than the 1991–2020 average (Mar 20).

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).

Soil in Piasa, IL

The soil mapped at the center of ZIP 62079 is Oconee — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH6.7neutral; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter2.5%moderate
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Oconee 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 62079; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Piasa, IL

Summer high87 °Faverage high, July
Winter low19 °Faverage low, January
Hot days29days a year at 90 °F or more
Freezing nights118nights a year at 32 °F or less
Growing degree days3,714base 50 °F — the season’s usable heat
Longest day14 h 55 mindaylight on June 21
Shortest day9 h 25 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation39.8 inper year, rain and melted snow
Snowfall17 inper year; 16 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 36 °F, low 19 °F 36°19° JanFebruary: average high 42 °F, low 23 °F 42°23° FebMarch: average high 53 °F, low 32 °F 53°32° MarApril: average high 65 °F, low 42 °F 65°42° AprMay: average high 74 °F, low 54 °F 74°54° MayJune: average high 83 °F, low 63 °F 83°63° JunJuly: average high 87 °F, low 66 °F 87°66° JulAugust: average high 85 °F, low 63 °F 85°63° AugSeptember: average high 79 °F, low 55 °F 79°55° SepOctober: average high 67 °F, low 43 °F 67°43° 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 · ❄ = snowfall

0″1″2″3″4″5″6″January: 2.49 in precipitation, 5.1 in snowfall 2.5❄5 JanFebruary: 2.21 in precipitation, 4.9 in snowfall 2.2❄5 FebMarch: 3.13 in precipitation, 2.4 in snowfall 3.1❄2 MarApril: 4.40 in precipitation, 0.2 in snowfall 4.4 AprMay: 5.18 in precipitation 5.2 MayJune: 3.23 in precipitation 3.2 JunJuly: 3.42 in precipitation 3.4 JulAugust: 3.52 in precipitation 3.5 AugSeptember: 3.20 in precipitation 3.2 SepOctober: 3.41 in precipitation 3.4 OctNovember: 3.13 in precipitation, 1.2 in snowfall 3.1❄1 NovDecember: 2.44 in precipitation, 2.7 in snowfall 2.4❄3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Jerseyville 2 Sw, IL (11 mi away); precipitation: Medora 1 S, IL (3 mi away). 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.

620126b
Brighton, IL · 4 mi
620636b
Medora, IL · 6 mi
626856b
Shipman, IL · 8 mi
620526b
Jerseyville, IL · 10 mi
620146b
Bunker Hill, IL · 11 mi
626306b
Chesterfield, IL · 12 mi
620027a
Alton, IL · 12 mi
620816b
Rockbridge, IL · 12 mi

Illinois planting zones →

Questions about 62079

What planting zone is ZIP code 62079?

ZIP code 62079 (Piasa, 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 Piasa, IL?

The median last spring frost (32 °F) near 62079 is April 14; after April 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Jerseyville 2 Sw station.

When is the first frost in Piasa, IL?

The median first fall frost near 62079 is October 19, giving a median frost-free growing season of 187 days.

When should I plant tomatoes in 62079?

Start tomato seeds indoors around Feb 17 – Mar 3 and set transplants outside around Apr 21 – May 5, one to three weeks after the median last frost.

How much rain and snow does 62079 get?

About 39.8 inches of precipitation a year and 17 inches of snowfall (NOAA 1991–2020 normals, Medora 1 S station).

How hot do summers get in Piasa, IL?

The average high peaks at 87 °F in July, with about 29 days a year at 90 °F or more.

What kind of soil does 62079 have?

The USDA soil survey maps Oconee at the center of ZIP 62079: silt loam, somewhat poorly drained, pH about 6.7 (neutral).

Did spring come early in Piasa, IL in 2026?

Spring leaf-out near 62079 came on Mar 8 in 2026, 12 days earlier than the 1991–2020 average (Mar 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Piasa, IL?

Intermediate onions: the longest day near 62079 is 14 h 55 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 62079 change?

Yes. The 2012 USDA map put 62079 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.