Planting zone for 62611 — Arenzville, IL
ZIP code 62611 (Arenzville, Cass County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 19 and the first fall frost October 17.
Where ZIP 62611 is
Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoomNot 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.
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 ServiceLoading the forecast for Arenzville, 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 Arenzville, IL
A hard freeze (28 °F) usually ends around April 7 and returns around October 27.
From the NOAA station Jacksonville 2e, IL — 15 miles away, elevation 610 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 62611
Counted from the median last spring frost (Apr 19) and first fall frost (Oct 17) 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 62611 came on Mar 10 — 16 days earlier than the 1991–2020 average (Mar 26).
Mar 262026
Mar 10
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 Arenzville, IL.
Soil in Arenzville, IL
The soil mapped at the center of ZIP 62611 is Littleton — silt loam, somewhat poorly drained.
Map unit: Littleton silt loam, 0 to 2 percent slopes, rarely flooded.
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 62611; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.
Climate in Arenzville, IL
Average high and low, by month
Precipitation by month inches
NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Jacksonville 2e, IL (15 mi away); precipitation: Arenzville 5.3 Nne, IL (6 mi away). Daylight is calculated from latitude.
Nearby ZIP codes
All 8 nearest ZIP codes share zone 6a.
Questions about 62611
What planting zone is ZIP code 62611?
ZIP code 62611 (Arenzville, 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 Arenzville, IL?
The median last spring frost (32 °F) near 62611 is April 19; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Jacksonville 2e station.
When is the first frost in Arenzville, IL?
The median first fall frost near 62611 is October 17, giving a median frost-free growing season of 179 days.
When should I plant tomatoes in 62611?
Start tomato seeds indoors around Feb 22 – Mar 8 and set transplants outside around Apr 26 – May 10, one to three weeks after the median last frost.
How much rain and snow does 62611 get?
About 40.5 inches of precipitation a year (NOAA 1991–2020 normals, Arenzville 5.3 Nne station).
How hot do summers get in Arenzville, IL?
The average high peaks at 87 °F in July, with about 28 days a year at 90 °F or more.
What kind of soil does 62611 have?
The USDA soil survey maps Littleton at the center of ZIP 62611: silt loam, somewhat poorly drained, pH about 6.7 (neutral).
Did spring come early in Arenzville, IL in 2026?
Spring leaf-out near 62611 came on Mar 10 in 2026, 16 days earlier than the 1991–2020 average (Mar 26), according to the USA National Phenology Network Spring Index.
What kind of onions grow in Arenzville, IL?
Long-day onions: the longest day near 62611 is 15 h 00 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).