Planting zone for 62234 — Collinsville, IL
ZIP code 62234 (Collinsville, Madison County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 8 and the first fall frost October 26.
Where ZIP 62234 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.
Was 6b 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 7a means →
Frost forecast — next 7 nights
live from the National Weather ServiceLoading the forecast for Collinsville, 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 Collinsville, IL
A hard freeze (28 °F) usually ends around March 28 and returns around November 6.
From the NOAA station Cahokia St Louis Airport, IL — 12 miles away, elevation 413 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 62234
Counted from the median last spring frost (Apr 8) and first fall frost (Oct 26) 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 62234 came on Mar 3 — 11 days earlier than the 1991–2020 average (Mar 14).
Mar 142026
Mar 3
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 7a in Illinois
633 plants native to the lower 48 states, recorded in Illinois, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.
Trees 81
Shrubs 110
Wildflowers & perennials 226
Grasses 186
Vines 13
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 Collinsville, IL.
Soil in Collinsville, IL
The soil mapped at the center of ZIP 62234 is Winfield — silt loam, moderately well drained.
Map unit: Winfield-Orthents-Urban land complex, 2 to 8 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 62234; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.
Climate in Collinsville, IL
Average high and low, by month
Precipitation by month inches
NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cahokia St Louis Airport, IL (12 mi away); precipitation: Fairview Heights 2.0 Ene, IL (6 mi away). Daylight is calculated from latitude.
Nearby ZIP codes
All 8 nearest ZIP codes share zone 7a.
Questions about 62234
What planting zone is ZIP code 62234?
ZIP code 62234 (Collinsville, IL) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).
When is the last frost in Collinsville, IL?
The median last spring frost (32 °F) near 62234 is April 8; after April 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cahokia St Louis Airport station.
When is the first frost in Collinsville, IL?
The median first fall frost near 62234 is October 26, giving a median frost-free growing season of 200 days.
When should I plant tomatoes in 62234?
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 62234 get?
About 43.6 inches of precipitation a year (NOAA 1991–2020 normals, Fairview Heights 2.0 Ene station).
How hot do summers get in Collinsville, IL?
The average high peaks at 89 °F in July, with about 46 days a year at 90 °F or more.
What kind of soil does 62234 have?
The USDA soil survey maps Winfield at the center of ZIP 62234: silt loam, moderately well drained, pH about 6.5 (neutral).
Did spring come early in Collinsville, IL in 2026?
Spring leaf-out near 62234 came on Mar 3 in 2026, 11 days earlier than the 1991–2020 average (Mar 14), according to the USA National Phenology Network Spring Index.
What kind of onions grow in Collinsville, IL?
Intermediate onions: the longest day near 62234 is 14 h 52 min, so day-neutral types bulb best; long-day varieties may not bulb fully.
Did the zone for 62234 change?
Yes. The 2012 USDA map put 62234 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.