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

Planting zone for 62306 — Quincy, IL

ZIP code 62306 (Quincy, Adams County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 8 and the first fall frost October 30.

Where ZIP 62306 is

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 8
First frostOct 30
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 Quincy, 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 Quincy, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 8median — 50% chance of a later frost
Safe for tender plantsApril 23only 10% chance of frost after
First fall frostOctober 30median — 10% chance by Oct 17
Growing season204 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 30 and returns around November 8.

From the NOAA station Quincy Dam 21, IL — 2 miles away, elevation 482 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 62306

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 25 – Mar 11
SpinachSow outdoors · Feb 25 – Mar 18
Broccoli, cabbageStart indoors · Jan 28 – Feb 11
Broccoli, cabbageTransplant · Mar 18 – Apr 1
Onion setsPlant outdoors · Mar 11 – Mar 25
PotatoesPlant outdoors · Mar 18 – Apr 1
LettuceSow outdoors · Mar 11 – Mar 25
Carrots, beetsSow outdoors · Mar 18 – Apr 1
TomatoesStart indoors · Feb 11 – Feb 25
TomatoesTransplant · Apr 15 – Apr 29
Peppers, eggplantStart indoors · Jan 28 – Feb 11
Peppers, eggplantTransplant · Apr 22 – May 6
BeansSow outdoors · Apr 15 – Apr 29
Sweet cornSow outdoors · Apr 15 – Apr 29
Cucumbers, squashSow outdoors · Apr 15 – Apr 29
Fall lettuce, spinachSow outdoors · Sep 4 – Sep 18
GarlicPlant cloves · Oct 16 – Nov 20
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 8) and first fall frost (Oct 30) 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 62306 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

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 220

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 178

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °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 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °F

Vines 9

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 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °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 Quincy, IL.

Soil in Quincy, IL

The soil mapped at the center of ZIP 62306 is Stookey — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH5.9moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Stookey-Timula-Orthents complex, 1 to 7 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 62306; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Quincy, IL

Summer high87 °Faverage high, July
Winter low19 °Faverage low, January
Hot days31days a year at 90 °F or more
Freezing nights112nights a year at 32 °F or less
Growing degree days3,861base 50 °F — the season’s usable heat
Longest day15 h 00 mindaylight on June 21
Shortest day9 h 20 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation36.5 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 35 °F, low 19 °F 35°19° JanFebruary: average high 40 °F, low 23 °F 40°23° FebMarch: average high 52 °F, low 32 °F 52°32° MarApril: average high 64 °F, low 43 °F 64°43° AprMay: average high 74 °F, low 54 °F 74°54° MayJune: average high 83 °F, low 64 °F 83°64° JunJuly: average high 87 °F, low 68 °F 87°68° JulAugust: average high 86 °F, low 66 °F 86°66° AugSeptember: average high 79 °F, low 57 °F 79°57° SepOctober: average high 67 °F, low 45 °F 67°45° OctNovember: average high 53 °F, low 34 °F 53°34° NovDecember: average high 40 °F, low 25 °F 40°25° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 1.66 in precipitation 1.7 JanFebruary: 1.91 in precipitation 1.9 FebMarch: 2.48 in precipitation 2.5 MarApril: 4.22 in precipitation 4.2 AprMay: 4.80 in precipitation 4.8 MayJune: 4.12 in precipitation 4.1 JunJuly: 3.64 in precipitation 3.6 JulAugust: 3.33 in precipitation 3.3 AugSeptember: 3.37 in precipitation 3.4 SepOctober: 2.65 in precipitation 2.6 OctNovember: 2.57 in precipitation 2.6 NovDecember: 1.73 in precipitation 1.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Quincy Dam 21, IL (2 mi away); precipitation: Quincy Dam 21, IL (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

623016a
Quincy, IL · 1 mi
623056a
Quincy, IL · 4 mi
634716a
Taylor, MO · 5 mi
634486a
La Grange, MO · 9 mi
623386a
Fowler, IL · 10 mi
623606a
Payson, IL · 11 mi
634616a
Palmyra, MO · 12 mi
623766a
Ursa, IL · 12 mi

All 3 ZIP codes in Quincy → · Illinois planting zones →

Questions about 62306

What planting zone is ZIP code 62306?

ZIP code 62306 (Quincy, 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 Quincy, IL?

The median last spring frost (32 °F) near 62306 is April 8; after April 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Quincy Dam 21 station.

When is the first frost in Quincy, IL?

The median first fall frost near 62306 is October 30, giving a median frost-free growing season of 204 days.

When should I plant tomatoes in 62306?

Start tomato seeds indoors around Feb 11 – Feb 25 and set transplants outside around Apr 15 – Apr 29, one to three weeks after the median last frost.

How much rain and snow does 62306 get?

About 36.5 inches of precipitation a year (NOAA 1991–2020 normals, Quincy Dam 21 station).

How hot do summers get in Quincy, IL?

The average high peaks at 87 °F in July, with about 31 days a year at 90 °F or more.

What kind of soil does 62306 have?

The USDA soil survey maps Stookey at the center of ZIP 62306: silt loam, well drained, pH about 5.9 (moderately acidic).

Did spring come early in Quincy, IL in 2026?

Spring leaf-out near 62306 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 Quincy, IL?

Long-day onions: the longest day near 62306 is 15 h 00 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).