Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 61701 — Bloomington, IL

ZIP code 61701 (Bloomington, McLean County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 21 and the first fall frost October 20.

Where ZIP 61701 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.

Zone6a−10 to −5 °F

Coldest night−23.3 to −20.6 °C

Last frostApr 21

First frostOct 20

2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Bloomington, 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 Bloomington, IL

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 21median — 50% chance of a later frost

Safe for tender plantsMay 5only 10% chance of frost after

First fall frostOctober 20median — 10% chance by Oct 9

Growing season181 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 9 and returns around October 30.

From the NOAA station Bloomington 5w, IL — 5 miles away, elevation 853 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 61701

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 10 – Mar 24

SpinachSow outdoors · Mar 10 – Mar 31

Broccoli, cabbageStart indoors · Feb 10 – Feb 24

Broccoli, cabbageTransplant · Mar 31 – Apr 14

Onion setsPlant outdoors · Mar 24 – Apr 7

PotatoesPlant outdoors · Mar 31 – Apr 14

LettuceSow outdoors · Mar 24 – Apr 7

Carrots, beetsSow outdoors · Mar 31 – Apr 14

TomatoesStart indoors · Feb 24 – Mar 10

TomatoesTransplant · Apr 28 – May 12

Peppers, eggplantStart indoors · Feb 10 – Feb 24

Peppers, eggplantTransplant · May 5 – May 19

BeansSow outdoors · Apr 28 – May 12

Sweet cornSow outdoors · Apr 28 – May 12

Cucumbers, squashSow outdoors · Apr 28 – May 12

Fall lettuce, spinachSow outdoors · Aug 25 – Sep 8

GarlicPlant cloves · Oct 6 – Nov 10

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 21) and first fall frost (Oct 20) 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 61701 came on Mar 11 — 20 days earlier than the 1991–2020 average (Mar 31).

average
Mar 312026
Mar 11

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.

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 Bloomington, IL.

Soil in Bloomington, IL

The soil mapped at the center of ZIP 61701 is Orthents — silty clay, moderately well drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureSilty clayholds water and nutrients; slow to drain and warm up

pH6.7neutral; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter1.25%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Urban land.

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 61701; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bloomington, IL

Summer high84 °Faverage high, July

Winter low16 °Faverage low, January

Hot days26days a year at 90 °F or more

Freezing nights132nights a year at 32 °F or less

Growing degree days3,204base 50 °F — the season’s usable heat

Longest day15 h 04 mindaylight on June 21

Shortest day9 h 17 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation38.5 inper year, rain and melted snow

Snowfall7 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Bloomington 5w, IL (5 mi away); precipitation: Bloomington Wtr Wks, IL (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

617106a

Bloomington, IL · 2 mi

617096a

Bloomington, IL · 2 mi

617046a

Bloomington, IL · 3 mi

617996a

Bloomington, IL · 3 mi

617616a

Normal, IL · 4 mi

617056a

Bloomington, IL · 5 mi

617726a

Shirley, IL · 7 mi

617026a

Bloomington, IL · 7 mi

All 8 ZIP codes in Bloomington → · Illinois planting zones →

Questions about 61701

What planting zone is ZIP code 61701?

ZIP code 61701 (Bloomington, 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 Bloomington, IL?

The median last spring frost (32 °F) near 61701 is April 21; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bloomington 5w station.

When is the first frost in Bloomington, IL?

The median first fall frost near 61701 is October 20, giving a median frost-free growing season of 181 days.

When should I plant tomatoes in 61701?

Start tomato seeds indoors around Feb 24 – Mar 10 and set transplants outside around Apr 28 – May 12, one to three weeks after the median last frost.

How much rain and snow does 61701 get?

About 38.5 inches of precipitation a year and 7 inches of snowfall (NOAA 1991–2020 normals, Bloomington Wtr Wks station).

How hot do summers get in Bloomington, IL?

The average high peaks at 84 °F in July, with about 26 days a year at 90 °F or more.

What kind of soil does 61701 have?

The USDA soil survey maps Orthents at the center of ZIP 61701: silty clay, moderately well drained, pH about 6.7 (neutral).

Did spring come early in Bloomington, IL in 2026?

Spring leaf-out near 61701 came on Mar 11 in 2026, 20 days earlier than the 1991–2020 average (Mar 31), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bloomington, IL?

Long-day onions: the longest day near 61701 is 15 h 04 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 61701 change?

Yes. The 2012 USDA map put 61701 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.