Frost dates 2026–2027

Frost dates for Bolingbrook, Illinois

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Romeoville WFO, 5.8 mi away (close match).

Last spring frostApr 20
First fall frostOct 22
184 frost-free days
Last spring frostApr 201 year in 10 after May 6
First fall frostOct 221 year in 10 by Oct 7
Growing season184 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 Bolingbrook 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 39°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 Bolingbrook

The median first fall hard-freeze date (28°F) is November 1, from NOAA’s 1991–2020 Climate Normals at Romeoville WFO. 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 17 · May 1 · May 17 Sep 28 · Oct 12 · Oct 24 162 days
32°F freeze Apr 7 · Apr 20 · May 6 Oct 7 · Oct 22 · Nov 3 184 days
28°F hard freeze Mar 27 · Apr 8 · Apr 23 Oct 19 · Nov 1 · Nov 15 206 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00117457. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Romeoville WFO

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 Bolingbrook, IL come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Romeoville WFO (station USC00117457, elevation 660 ft), 5.8 mi from Bolingbrook. 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 Bolingbrook

CityDistanceLast spring frostFirst fall frost
Romeoville, IL 4.3 mi Apr 20 Oct 22
Woodridge, IL 5.0 mi Apr 28 Oct 16
Naperville, IL 5.0 mi Apr 28 Oct 16
Lemont, IL 6.2 mi Apr 19 Oct 22
Lisle, IL 7.5 mi Apr 28 Oct 16
Darien, IL 7.5 mi Apr 19 Oct 22
Lockport, IL 7.5 mi Apr 20 Oct 22
Plainfield, IL 8.1 mi Apr 20 Oct 22
Crest Hill, IL 8.1 mi Apr 20 Oct 22
Downers Grove, IL 8.7 mi Apr 28 Oct 16

Frequently asked questions

When is the last frost in Bolingbrook?

On average, the last spring frost (32°F) in Bolingbrook is around April 20. In about 1 year in 10 it comes after May 6, and in 9 years in 10 it comes after April 7.

When is the first frost in Bolingbrook?

The first fall frost (32°F) usually arrives around October 22. There’s a 10% chance of a freeze by October 7 and a 90% chance by November 3.

Can it frost in Bolingbrook 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 Bolingbrook?

Bolingbrook 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 60440. See growing zones in Illinois.

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