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

Planting zone for 62923 — Cypress, IL

ZIP code 62923 (Cypress, Johnson County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 3 and the first fall frost November 5.

Where ZIP 62923 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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostApr 3
First frostNov 5
2012 zone7a

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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Cypress, 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 Cypress, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 3median — 50% chance of a later frost
Safe for tender plantsApril 21only 10% chance of frost after
First fall frostNovember 5median — 10% chance by Oct 23
Growing season216 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 22 and returns around November 17.

From the NOAA station Grand Chain Dam 53, IL — 9 miles away, elevation 384 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 62923

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 20 – Mar 6
SpinachSow outdoors · Feb 20 – Mar 13
Broccoli, cabbageStart indoors · Jan 23 – Feb 6
Broccoli, cabbageTransplant · Mar 13 – Mar 27
Onion setsPlant outdoors · Mar 6 – Mar 20
PotatoesPlant outdoors · Mar 13 – Mar 27
LettuceSow outdoors · Mar 6 – Mar 20
Carrots, beetsSow outdoors · Mar 13 – Mar 27
TomatoesStart indoors · Feb 6 – Feb 20
TomatoesTransplant · Apr 10 – Apr 24
Peppers, eggplantStart indoors · Jan 23 – Feb 6
Peppers, eggplantTransplant · Apr 17 – May 1
BeansSow outdoors · Apr 10 – Apr 24
Sweet cornSow outdoors · Apr 10 – Apr 24
Cucumbers, squashSow outdoors · Apr 10 – Apr 24
Fall lettuce, spinachSow outdoors · Sep 10 – Sep 24
GarlicPlant cloves · Oct 22 – Nov 26
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 3) and first fall frost (Nov 5) 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 62923 came on Mar 1 — 5 days earlier than the 1991–2020 average (Mar 6).

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 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 Cypress, IL.

Soil in Cypress, IL

The soil mapped at the center of ZIP 62923 is Hosmer — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH5.5moderately acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Hosmer silt loam, 10 to 18 percent slopes, severely eroded.

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 62923; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Cypress, IL

Summer high89 °Faverage high, July
Winter low26 °Faverage low, January
Hot days41days a year at 90 °F or more
Freezing nights80nights a year at 32 °F or less
Growing degree days4,461base 50 °F — the season’s usable heat
Longest day14 h 44 mindaylight on June 21
Shortest day9 h 35 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation49.4 inper year, rain and melted snow
Snowfall7 inper year; 7 days with snow on the ground

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 43 °F, low 26 °F 43°26° JanFebruary: average high 48 °F, low 30 °F 48°30° FebMarch: average high 57 °F, low 37 °F 57°37° MarApril: average high 68 °F, low 47 °F 68°47° AprMay: average high 77 °F, low 56 °F 77°56° MayJune: average high 86 °F, low 65 °F 86°65° JunJuly: average high 89 °F, low 69 °F 89°69° JulAugust: average high 89 °F, low 67 °F 89°67° AugSeptember: average high 83 °F, low 60 °F 83°60° SepOctober: average high 71 °F, low 48 °F 71°48° OctNovember: average high 58 °F, low 39 °F 58°39° NovDecember: average high 47 °F, low 31 °F 47°31° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 4.23 in precipitation, 2.1 in snowfall 4.2❄2 JanFebruary: 3.86 in precipitation, 2.5 in snowfall 3.9❄3 FebMarch: 4.77 in precipitation, 0.7 in snowfall 4.8❄1 MarApril: 5.15 in precipitation 5.2 AprMay: 4.92 in precipitation 4.9 MayJune: 4.13 in precipitation 4.1 JunJuly: 3.28 in precipitation 3.3 JulAugust: 3.03 in precipitation 3.0 AugSeptember: 3.35 in precipitation 3.4 SepOctober: 4.04 in precipitation, 0.1 in snowfall 4.0 OctNovember: 4.41 in precipitation 4.4 NovDecember: 4.24 in precipitation, 1.8 in snowfall 4.2❄2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Grand Chain Dam 53, IL (9 mi away); precipitation: Grand Chain Dam 53, IL (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

Illinois planting zones →

Questions about 62923

What planting zone is ZIP code 62923?

ZIP code 62923 (Cypress, 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 Cypress, IL?

The median last spring frost (32 °F) near 62923 is April 3; after April 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Grand Chain Dam 53 station.

When is the first frost in Cypress, IL?

The median first fall frost near 62923 is November 5, giving a median frost-free growing season of 216 days.

When should I plant tomatoes in 62923?

Start tomato seeds indoors around Feb 6 – Feb 20 and set transplants outside around Apr 10 – Apr 24, one to three weeks after the median last frost.

How much rain and snow does 62923 get?

About 49.4 inches of precipitation a year and 7 inches of snowfall (NOAA 1991–2020 normals, Grand Chain Dam 53 station).

How hot do summers get in Cypress, IL?

The average high peaks at 89 °F in July, with about 41 days a year at 90 °F or more.

What kind of soil does 62923 have?

The USDA soil survey maps Hosmer at the center of ZIP 62923: silt loam, moderately well drained, pH about 5.5 (moderately acidic).

Did spring come early in Cypress, IL in 2026?

Spring leaf-out near 62923 came on Mar 1 in 2026, 5 days earlier than the 1991–2020 average (Mar 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Cypress, IL?

Intermediate onions: the longest day near 62923 is 14 h 44 min, so day-neutral types bulb best; long-day varieties may not bulb fully.