Frost dates 2026–2027

Frost dates for New Lenox, Illinois

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Joliet Brandon Rd Dam, 6.9 mi away (close match).

Last spring frostApr 19
First fall frostOct 25
188 frost-free days
Last spring frostApr 191 year in 10 after May 7
First fall frostOct 251 year in 10 by Oct 12
Growing season188 daysbetween median 32°F dates
Hardiness zoneZone 6a−10 to −5°F average extreme low

Checking current alerts… View NWS forecast and alerts.

Will it freeze in New Lenox in the next 7 nights?

The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 32°F (Fri, Nov 6, 6:00 PM CST to Sat, Nov 7, 6:00 AM CST).

Tonight: forecast low 40°F. Above 36°F.

NWS forecast period: Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST.

3 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.

Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.

Frost and freeze probabilities

Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.

These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.

Average first hard freeze in New Lenox

The median first fall hard-freeze date (28°F) is November 4, from NOAA’s 1991–2020 Climate Normals at Joliet Brandon Rd Dam. This is the 50% probability date, not a forecast for this year.

TemperatureLast spring date
90% · 50% · 10% chance of a later freeze
First fall date
10% · 50% · 90% chance of an earlier freeze
Season
36°F frost possible Apr 16 · May 1 · May 18 Oct 2 · Oct 15 · Oct 27 166 days
32°F freeze Apr 3 · Apr 19 · May 7 Oct 12 · Oct 25 · Nov 6 188 days
28°F hard freeze Mar 22 · Apr 5 · Apr 21 Oct 23 · Nov 4 · Nov 21 211 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00114530. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Joliet Brandon Rd Dam

Average low temperature by month

Months with lows near or below freezing carry frost risk

Where these frost dates come from

The frost dates for New Lenox, IL come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Joliet Brandon Rd Dam (station USC00114530, elevation 543 ft), 6.9 mi from New Lenox. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.

Frost dates near New Lenox

CityDistanceLast spring frostFirst fall frost
Mokena, IL 5.0 mi Apr 23 Oct 20
Frankfort, IL 5.0 mi Apr 23 Oct 20
Manhattan, IL 6.2 mi Apr 19 Oct 25
Lockport, IL 6.2 mi Apr 20 Oct 22
Homer Glen, IL 6.8 mi Apr 20 Oct 22
Crest Hill, IL 8.7 mi Apr 20 Oct 22
Orland Hills, IL 8.7 mi Apr 19 Oct 22
Orland Park, IL 8.7 mi Apr 19 Oct 22
Joliet, IL 9.3 mi Apr 19 Oct 25
Tinley Park, IL 9.3 mi Apr 23 Oct 20

Frequently asked questions

When is the last frost in New Lenox?

On average, the last spring frost (32°F) in New Lenox is around April 19. In about 1 year in 10 it comes after May 7, and in 9 years in 10 it comes after April 3.

When is the first frost in New Lenox?

The first fall frost (32°F) usually arrives around October 25. There’s a 10% chance of a freeze by October 12 and a 90% chance by November 6.

Can it frost in New Lenox after the last frost date?

Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after May 1.

What growing zone is New Lenox?

New Lenox is in USDA Plant Hardiness Zone 6a (average annual extreme minimum temperature −10 to −5°F), based on the 2023 USDA map for ZIP code 60451. See growing zones in Illinois.

More: all Illinois frost dates · Illinois growing zones · UV index today in New Lenox · frost vs. freeze