Frost dates 2026–2027

Frost dates for Mokena, Illinois

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Park Forest, 11 mi away (close match).

Last spring frostApr 23
First fall frostOct 20
179 frost-free days
Last spring frostApr 231 year in 10 after May 11
First fall frostOct 201 year in 10 by Oct 6
Growing season179 daysbetween median 32°F dates
Hardiness zoneZone 6a−10 to −5°F average extreme low

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Will it freeze in Mokena 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 Mokena

The median first fall hard-freeze date (28°F) is October 30, from NOAA’s 1991–2020 Climate Normals at Park Forest. 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 20 · May 5 · May 24 Sep 27 · Oct 10 · Oct 22 157 days
32°F freeze Apr 9 · Apr 23 · May 11 Oct 6 · Oct 20 · Nov 1 179 days
28°F hard freeze Mar 30 · Apr 12 · Apr 27 Oct 18 · Oct 30 · Nov 15 202 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00116616. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Park Forest

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 Mokena, IL come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Park Forest (station USC00116616, elevation 710 ft), 11 mi from Mokena. 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 Mokena

CityDistanceLast spring frostFirst fall frost
Frankfort, IL 1.9 mi Apr 23 Oct 20
Orland Hills, IL 4.3 mi Apr 19 Oct 22
Tinley Park, IL 4.3 mi Apr 23 Oct 20
New Lenox, IL 5.0 mi Apr 19 Oct 25
Orland Park, IL 5.6 mi Apr 19 Oct 22
Homer Glen, IL 6.2 mi Apr 20 Oct 22
Matteson, IL 6.8 mi Apr 23 Oct 20
Richton Park, IL 8.1 mi Apr 23 Oct 20
Country Club Hills, IL 8.1 mi Apr 23 Oct 20
Oak Forest, IL 8.1 mi Apr 23 Oct 20

Frequently asked questions

When is the last frost in Mokena?

On average, the last spring frost (32°F) in Mokena is around April 23. In about 1 year in 10 it comes after May 11, and in 9 years in 10 it comes after April 9.

When is the first frost in Mokena?

The first fall frost (32°F) usually arrives around October 20. There’s a 10% chance of a freeze by October 6 and a 90% chance by November 1.

Can it frost in Mokena 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 5.

What growing zone is Mokena?

Mokena 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 60448. See growing zones in Illinois.

More: all Illinois frost dates · Illinois growing zones · frost vs. freeze