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

Planting zone for 61864 — Philo, IL

ZIP code 61864 (Philo, Champaign 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 61864 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 19

First frostOct 17

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 Philo, 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 Philo, IL

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 19median — 50% chance of a later frost

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

First fall frostOctober 17median — 10% chance by Oct 3

Growing season180 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 8 and returns around October 28.

From the NOAA station Champaign Willard Airport, IL — 8 miles away, elevation 755 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 61864

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 8 – Mar 22

SpinachSow outdoors · Mar 8 – Mar 29

Broccoli, cabbageStart indoors · Feb 8 – Feb 22

Broccoli, cabbageTransplant · Mar 29 – Apr 12

Onion setsPlant outdoors · Mar 22 – Apr 5

PotatoesPlant outdoors · Mar 29 – Apr 12

LettuceSow outdoors · Mar 22 – Apr 5

Carrots, beetsSow outdoors · Mar 29 – Apr 12

TomatoesStart indoors · Feb 22 – Mar 8

TomatoesTransplant · Apr 26 – May 10

Peppers, eggplantStart indoors · Feb 8 – Feb 22

Peppers, eggplantTransplant · May 3 – May 17

BeansSow outdoors · Apr 26 – May 10

Sweet cornSow outdoors · Apr 26 – May 10

Cucumbers, squashSow outdoors · Apr 26 – May 10

Fall lettuce, spinachSow outdoors · Aug 22 – Sep 5

GarlicPlant cloves · Oct 3 – Nov 7

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

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 61864 came on Mar 10 — 18 days earlier than the 1991–2020 average (Mar 28).

average
Mar 282026
Mar 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 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 Philo, IL.

Soil in Philo, IL

The soil mapped at the center of ZIP 61864 is Elburn — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables

pH6.7neutral; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter4.5%moderate

Hydrologic groupB/Dmoderate when drained; wet otherwise

Farmland classprime farmlandUSDA classification

Map unit: Elburn silt loam, 0 to 2 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 61864; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Philo, IL

Summer high85 °Faverage high, July

Winter low18 °Faverage low, January

Hot days22days a year at 90 °F or more

Freezing nights122nights a year at 32 °F or less

Growing degree days3,574base 50 °F — the season’s usable heat

Longest day15 h 01 mindaylight on June 21

Shortest day9 h 20 mindaylight on December 21

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

Precipitation39.5 inper year, rain and melted snow

Snowfall21 inper year; 32 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Champaign Willard Airport, IL (8 mi away); precipitation: Philo, IL (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

Villa Grove, IL · 8 mi

Broadlands, IL · 9 mi

618016a

Urbana, IL · 10 mi

Illinois planting zones →

Questions about 61864

What planting zone is ZIP code 61864?

ZIP code 61864 (Philo, 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 Philo, IL?

The median last spring frost (32 °F) near 61864 is April 19; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Champaign Willard Airport station.

When is the first frost in Philo, IL?

The median first fall frost near 61864 is October 17, giving a median frost-free growing season of 180 days.

When should I plant tomatoes in 61864?

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 61864 get?

About 39.5 inches of precipitation a year and 21 inches of snowfall (NOAA 1991–2020 normals, Philo station).

How hot do summers get in Philo, IL?

The average high peaks at 85 °F in July, with about 22 days a year at 90 °F or more.

What kind of soil does 61864 have?

The USDA soil survey maps Elburn at the center of ZIP 61864: silt loam, somewhat poorly drained, pH about 6.7 (neutral).

Did spring come early in Philo, IL in 2026?

Spring leaf-out near 61864 came on Mar 10 in 2026, 18 days earlier than the 1991–2020 average (Mar 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Philo, IL?

Long-day onions: the longest day near 61864 is 15 h 01 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 61864 change?

Yes. The 2012 USDA map put 61864 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.