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

Planting zone for 62674 — Palmyra, IL

ZIP code 62674 (Palmyra, 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 21.

Where ZIP 62674 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 21
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 Palmyra, 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 Palmyra, 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 21median — 10% chance by Oct 5
Growing season188 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 2 and returns around November 1.

From the NOAA station Carlinville, IL — 13 miles away, elevation 620 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 62674

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 26 – Sep 9
GarlicPlant cloves · Oct 7 – Nov 11
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 14) and first fall frost (Oct 21) 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 62674 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 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 Palmyra, IL.

Soil in Palmyra, IL

The soil mapped at the center of ZIP 62674 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 62674; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Palmyra, IL

Summer high86 °Faverage high, July
Winter low19 °Faverage low, January
Hot days27days a year at 90 °F or more
Freezing nights110nights a year at 32 °F or less
Growing degree days3,725base 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
Precipitation40.1 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 23 °F 41°23° FebMarch: average high 52 °F, low 32 °F 52°32° MarApril: average high 65 °F, low 43 °F 65°43° AprMay: average high 74 °F, low 54 °F 74°54° MayJune: average high 83 °F, low 63 °F 83°63° JunJuly: average high 86 °F, low 66 °F 86°66° JulAugust: average high 85 °F, low 64 °F 85°64° AugSeptember: average high 79 °F, low 55 °F 79°55° SepOctober: average high 67 °F, low 44 °F 67°44° OctNovember: average high 53 °F, low 33 °F 53°33° NovDecember: average high 41 °F, low 25 °F 41°25° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.16 in precipitation 2.2 JanFebruary: 1.87 in precipitation 1.9 FebMarch: 3.17 in precipitation 3.2 MarApril: 4.27 in precipitation 4.3 AprMay: 4.85 in precipitation 4.8 MayJune: 4.63 in precipitation 4.6 JunJuly: 3.75 in precipitation 3.8 JulAugust: 3.43 in precipitation 3.4 AugSeptember: 3.34 in precipitation 3.3 SepOctober: 3.52 in precipitation 3.5 OctNovember: 3.12 in precipitation 3.1 NovDecember: 2.01 in precipitation 2.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Carlinville, IL (13 mi away); precipitation: Girard 1.2 W, IL (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

626676b
Modesto, IL · 4 mi
626836b
Scottville, IL · 5 mi
626496a
Hettick, IL · 6 mi
626926a
Waverly, IL · 11 mi
620446a
Greenfield, IL · 11 mi
626406b
Girard, IL · 12 mi
626386a
Franklin, IL · 12 mi
626726b
Nilwood, IL · 12 mi

Illinois planting zones →

Questions about 62674

What planting zone is ZIP code 62674?

ZIP code 62674 (Palmyra, 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 Palmyra, IL?

The median last spring frost (32 °F) near 62674 is April 14; after April 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Carlinville station.

When is the first frost in Palmyra, IL?

The median first fall frost near 62674 is October 21, giving a median frost-free growing season of 188 days.

When should I plant tomatoes in 62674?

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 62674 get?

About 40.1 inches of precipitation a year (NOAA 1991–2020 normals, Girard 1.2 W station).

How hot do summers get in Palmyra, IL?

The average high peaks at 86 °F in July, with about 27 days a year at 90 °F or more.

What kind of soil does 62674 have?

The USDA soil survey maps Ipava at the center of ZIP 62674: silt loam, somewhat poorly drained, pH about 5.8 (moderately acidic).

Did spring come early in Palmyra, IL in 2026?

Spring leaf-out near 62674 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 Palmyra, IL?

Intermediate onions: the longest day near 62674 is 14 h 57 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 62674 change?

Yes. The 2012 USDA map put 62674 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.