Frost dates 2026–2027

Frost dates for Warrenville, Illinois

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Lisle-Morton Arboretum, 5.9 mi away (close match).

Last spring frostApr 28
First fall frostOct 16
169 frost-free days
Last spring frostApr 281 year in 10 after May 14
First fall frostOct 161 year in 10 by Oct 1
Growing season169 daysbetween median 32°F dates
Hardiness zoneZone 5b−15 to −10°F average extreme low

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Will it freeze in Warrenville 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 38°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 Warrenville

The median first fall hard-freeze date (28°F) is October 26, from NOAA’s 1991–2020 Climate Normals at Lisle-Morton Arboretum. 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 25 · May 9 · May 25 Sep 22 · Oct 6 · Oct 18 148 days
32°F freeze Apr 14 · Apr 28 · May 14 Oct 1 · Oct 16 · Oct 29 169 days
28°F hard freeze Apr 2 · Apr 16 · May 4 Oct 12 · Oct 26 · Nov 8 190 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00115097. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Lisle-Morton Arboretum

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 Warrenville, IL come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Lisle-Morton Arboretum (station USC00115097, elevation 680 ft), 5.9 mi from Warrenville. 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 Warrenville

CityDistanceLast spring frostFirst fall frost
Winfield, IL 4.3 mi Apr 25 Oct 19
Wheaton, IL 5.0 mi Apr 28 Oct 16
Naperville, IL 5.0 mi Apr 28 Oct 16
West Chicago, IL 5.6 mi Apr 25 Oct 19
Lisle, IL 5.6 mi Apr 28 Oct 16
Aurora, IL 6.8 mi Apr 19 Oct 23
Batavia, IL 6.8 mi Apr 19 Oct 23
Glen Ellyn, IL 7.5 mi Apr 28 Oct 16
Carol Stream, IL 7.5 mi Apr 25 Oct 19
North Aurora, IL 8.1 mi Apr 19 Oct 23

Frequently asked questions

When is the last frost in Warrenville?

On average, the last spring frost (32°F) in Warrenville is around April 28. In about 1 year in 10 it comes after May 14, and in 9 years in 10 it comes after April 14.

When is the first frost in Warrenville?

The first fall frost (32°F) usually arrives around October 16. There’s a 10% chance of a freeze by October 1 and a 90% chance by October 29.

Can it frost in Warrenville 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 9.

What growing zone is Warrenville?

Warrenville is in USDA Plant Hardiness Zone 5b (average annual extreme minimum temperature −15 to −10°F), based on the 2023 USDA map for ZIP code 60555. See growing zones in Illinois.

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