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

Planting zone for 61272 — New Boston, IL

ZIP code 61272 (New Boston, Mercer County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 14 and the first fall frost October 24.

Where ZIP 61272 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.

Zone5b−15 to −10 °F
Coldest night−26.1 to −23.3 °C
Last frostApr 14
First frostOct 24
2012 zone5b

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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for New Boston, 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 New Boston, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 14median — 50% chance of a later frost
Safe for tender plantsMay 2only 10% chance of frost after
First fall frostOctober 24median — 10% chance by Oct 9
Growing season190 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around November 1.

From the NOAA station New Boston Dam 17, IL — 5 miles away, elevation 548 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 61272

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 3 – Mar 17
SpinachSow outdoors · Mar 3 – Mar 24
Broccoli, cabbageStart indoors · Feb 3 – Feb 17
Broccoli, cabbageTransplant · Mar 24 – Apr 7
Onion setsPlant outdoors · Mar 17 – Mar 31
PotatoesPlant outdoors · Mar 24 – Apr 7
LettuceSow outdoors · Mar 17 – Mar 31
Carrots, beetsSow outdoors · Mar 24 – Apr 7
TomatoesStart indoors · Feb 17 – Mar 3
TomatoesTransplant · Apr 21 – May 5
Peppers, eggplantStart indoors · Feb 3 – Feb 17
Peppers, eggplantTransplant · Apr 28 – May 12
BeansSow outdoors · Apr 21 – May 5
Sweet cornSow outdoors · Apr 21 – May 5
Cucumbers, squashSow outdoors · Apr 21 – May 5
Fall lettuce, spinachSow outdoors · Aug 29 – Sep 12
GarlicPlant cloves · Oct 10 – Nov 14
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 14) and first fall frost (Oct 24) 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 61272 came on Mar 15 — 19 days earlier than the 1991–2020 average (Apr 3).

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

Shrubs 102

Wildflowers & perennials 210

Grasses 173

Vines 7

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 New Boston, IL.

Soil in New Boston, IL

The soil mapped at the center of ZIP 61272 is Coloma — sand, excessively drained.

TextureSanddrains and warms fast; dries out and needs more feeding
pH5.9moderately acidic; most vegetables like 6.0–7.0
DrainageExcessively drainednatural drainage class
Organic matter1.25%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Coloma sand, 1 to 7 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 61272; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in New Boston, IL

Summer high86 °Faverage high, July
Winter low15 °Faverage low, January
Hot days24days a year at 90 °F or more
Freezing nights122nights a year at 32 °F or less
Growing degree days3,439base 50 °F — the season’s usable heat
Longest day15 h 09 mindaylight on June 21
Shortest day9 h 12 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation36.3 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 32 °F, low 15 °F 32°15° JanFebruary: average high 36 °F, low 19 °F 36°19° FebMarch: average high 49 °F, low 30 °F 49°30° MarApril: average high 62 °F, low 40 °F 62°40° AprMay: average high 73 °F, low 52 °F 73°52° MayJune: average high 83 °F, low 62 °F 83°62° JunJuly: average high 86 °F, low 65 °F 86°65° JulAugust: average high 84 °F, low 63 °F 84°63° AugSeptember: average high 77 °F, low 55 °F 77°55° SepOctober: average high 64 °F, low 43 °F 64°43° OctNovember: average high 49 °F, low 32 °F 49°32° NovDecember: average high 37 °F, low 22 °F 37°22° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 1.31 in precipitation 1.3 JanFebruary: 1.72 in precipitation 1.7 FebMarch: 2.62 in precipitation 2.6 MarApril: 3.56 in precipitation 3.6 AprMay: 5.05 in precipitation 5.0 MayJune: 4.59 in precipitation 4.6 JunJuly: 3.52 in precipitation 3.5 JulAugust: 3.83 in precipitation 3.8 AugSeptember: 3.34 in precipitation 3.3 SepOctober: 2.86 in precipitation 2.9 OctNovember: 2.13 in precipitation 2.1 NovDecember: 1.77 in precipitation 1.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: New Boston Dam 17, IL (5 mi away); precipitation: New Boston Dam 17, IL (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

Illinois planting zones →

Questions about 61272

What planting zone is ZIP code 61272?

ZIP code 61272 (New Boston, IL) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in New Boston, IL?

The median last spring frost (32 °F) near 61272 is April 14; after May 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, New Boston Dam 17 station.

When is the first frost in New Boston, IL?

The median first fall frost near 61272 is October 24, giving a median frost-free growing season of 190 days.

When should I plant tomatoes in 61272?

Start tomato seeds indoors around Feb 17 – Mar 3 and set transplants outside around Apr 21 – May 5, one to three weeks after the median last frost.

How much rain and snow does 61272 get?

About 36.3 inches of precipitation a year (NOAA 1991–2020 normals, New Boston Dam 17 station).

How hot do summers get in New Boston, IL?

The average high peaks at 86 °F in July, with about 24 days a year at 90 °F or more.

What kind of soil does 61272 have?

The USDA soil survey maps Coloma at the center of ZIP 61272: sand, excessively drained, pH about 5.9 (moderately acidic).

Did spring come early in New Boston, IL in 2026?

Spring leaf-out near 61272 came on Mar 15 in 2026, 19 days earlier than the 1991–2020 average (Apr 3), according to the USA National Phenology Network Spring Index.

What kind of onions grow in New Boston, IL?

Long-day onions: the longest day near 61272 is 15 h 09 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).