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

Planting zone for Crystal Lake, IL

Crystal Lake, IL is in USDA zone 5b across its 3 ZIP codes. The median last spring frost is April 25 and the first fall frost October 22.

Crystal Lake on the zone map

Outlined: its 2 ZIP code areas · 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.

Zone5b−15 to −10 °F
ZIP codes3
Last frostApr 25
First frostOct 22
Growing season179 days

5b 3 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Crystal Lake, 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 Crystal Lake, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 25median — 50% chance of a later frost
Safe for tender plantsMay 9only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 7
Growing season179 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 12 and returns around November 1.

From the NOAA station Crystal Lake 4nw, IL, elevation 942 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 Crystal Lake

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 14 – Mar 28
SpinachSow outdoors · Mar 14 – Apr 4
Broccoli, cabbageStart indoors · Feb 14 – Feb 28
Broccoli, cabbageTransplant · Apr 4 – Apr 18
Onion setsPlant outdoors · Mar 28 – Apr 11
PotatoesPlant outdoors · Apr 4 – Apr 18
LettuceSow outdoors · Mar 28 – Apr 11
Carrots, beetsSow outdoors · Apr 4 – Apr 18
TomatoesStart indoors · Feb 28 – Mar 14
TomatoesTransplant · May 2 – May 16
Peppers, eggplantStart indoors · Feb 14 – Feb 28
Peppers, eggplantTransplant · May 9 – May 23
BeansSow outdoors · May 2 – May 16
Sweet cornSow outdoors · May 2 – May 16
Cucumbers, squashSow outdoors · May 2 – May 16
Fall lettuce, spinachSow outdoors · Aug 27 – Sep 10
GarlicPlant cloves · Oct 8 – Nov 12
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 25) and first fall frost (Oct 22) 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 60012 came on Mar 25 — 16 days earlier than the 1991–2020 average (Apr 10).

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 5b in Illinois

584 plants native to the lower 48 states, recorded in Illinois, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.

Trees 77

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 102

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 210

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 173

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 7

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °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 °Ftrumpet honeysuckle16 ft · blooms late summer · low shade tolerance · to −33 °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 Crystal Lake, IL.

Soil in Crystal Lake, IL

The soil mapped at the center of ZIP 60012 is McHenry — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH6.5neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: McHenry silt loam, 2 to 4 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 60012; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Crystal Lake, IL

Summer high84 °Faverage high, July
Winter low13 °Faverage low, January
Hot days11days a year at 90 °F or more
Freezing nights144nights a year at 32 °F or less
Growing degree days2,891base 50 °F — the season’s usable heat
Longest day15 h 16 mindaylight on June 21
Shortest day9 h 05 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation37 inper year, rain and melted snow
Snowfall35 inper year; 55 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 31 °F, low 13 °F 31°13° JanFebruary: average high 35 °F, low 16 °F 35°16° FebMarch: average high 46 °F, low 26 °F 46°26° MarApril: average high 59 °F, low 37 °F 59°37° AprMay: average high 70 °F, low 47 °F 70°47° MayJune: average high 80 °F, low 57 °F 80°57° JunJuly: average high 84 °F, low 62 °F 84°62° JulAugust: average high 82 °F, low 60 °F 82°60° AugSeptember: average high 76 °F, low 51 °F 76°51° SepOctober: average high 63 °F, low 40 °F 63°40° OctNovember: average high 48 °F, low 29 °F 48°29° NovDecember: average high 36 °F, low 19 °F 36°19° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 1.65 in precipitation, 11 in snowfall 1.6❄11 JanFebruary: 1.56 in precipitation, 8.9 in snowfall 1.6❄9 FebMarch: 2.21 in precipitation, 3.9 in snowfall 2.2❄4 MarApril: 3.63 in precipitation, 1 in snowfall 3.6❄1 AprMay: 4.47 in precipitation 4.5 MayJune: 4.81 in precipitation 4.8 JunJuly: 3.80 in precipitation 3.8 JulAugust: 3.70 in precipitation 3.7 AugSeptember: 3.61 in precipitation 3.6 SepOctober: 3.21 in precipitation, 0.1 in snowfall 3.2 OctNovember: 2.38 in precipitation, 1.4 in snowfall 2.4❄1 NovDecember: 1.94 in precipitation, 8.2 in snowfall 1.9❄8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Mc Henry -Wg Stratton L&D, IL (4 mi away); precipitation: Mc Henry -Wg Stratton L&D, IL (4 mi away). Daylight is calculated from latitude.

ZIP codes in Crystal Lake

600125b
−15 to −10 °F
600145b
−15 to −10 °F
600395b
−15 to −10 °F

Illinois planting zones →

Questions about Crystal Lake

What planting zone is Crystal Lake, IL?

Crystal Lake, IL is in USDA hardiness zone 5b on the 2023 map (5b: −15 to −10 °F).

When is the last frost in Crystal Lake, IL?

The median last spring frost is April 25 and the median first fall frost is October 22 (NOAA 1991–2020 normals, Crystal Lake 4nw station).

When can I plant a garden in Crystal Lake, IL?

Cool-season crops like peas and spinach go in around Mar 14 – Apr 4; tomatoes, peppers, beans and squash after about May 2, once frost risk has passed.

What kind of onions grow in Crystal Lake, IL?

Long-day onions: the longest day is 15 h 16 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Crystal Lake, IL get?

About 37 inches of precipitation a year and 35 inches of snowfall (NOAA 1991–2020 normals).