Frost dates 2026–2027

Frost dates for Rochelle, Illinois

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Rochelle, 0.6 mi away (close match).

Last spring frostApr 26
First fall frostOct 13
168 frost-free days
Last spring frostApr 261 year in 10 after May 12
First fall frostOct 131 year in 10 by Sep 29
Growing season168 daysbetween median 32°F dates
Hardiness zoneZone 5b−15 to −10°F average extreme low

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Will it freeze in Rochelle in the next 7 nights?

The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 27°F (Fri, Nov 6, 6:00 PM CST to Sat, Nov 7, 6:00 AM CST).

Tonight: forecast low 36°F. Frost possible.

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

4 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 Rochelle

The median first fall hard-freeze date (28°F) is October 24, from NOAA’s 1991–2020 Climate Normals at Rochelle. 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 22 · May 5 · May 21 Sep 19 · Oct 3 · Oct 15 148 days
32°F freeze Apr 11 · Apr 26 · May 12 Sep 29 · Oct 13 · Oct 25 168 days
28°F hard freeze Mar 31 · Apr 14 · Apr 30 Oct 11 · Oct 24 · Nov 5 191 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00117354. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Rochelle

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 Rochelle, IL come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Rochelle (station USC00117354, elevation 775 ft), 0.6 mi from Rochelle. 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 Rochelle

CityDistanceLast spring frostFirst fall frost
DeKalb, IL 16 mi Apr 24 Oct 18
Sycamore, IL 21 mi Apr 24 Oct 18
Dixon, IL 22 mi Apr 21 Oct 19
Genoa, IL 22 mi Apr 24 Oct 18
Rockford, IL 24 mi Apr 24 Oct 17
Mendota, IL 25 mi Apr 27 Oct 15
Belvidere, IL 25 mi Apr 24 Oct 17
Loves Park, IL 29 mi Apr 24 Oct 17
Sandwich, IL 29 mi Apr 28 Oct 13
Machesney Park, IL 31 mi May 1 Oct 12

Frequently asked questions

When is the last frost in Rochelle?

On average, the last spring frost (32°F) in Rochelle is around April 26. In about 1 year in 10 it comes after May 12, and in 9 years in 10 it comes after April 11.

When is the first frost in Rochelle?

The first fall frost (32°F) usually arrives around October 13. There’s a 10% chance of a freeze by September 29 and a 90% chance by October 25.

Can it frost in Rochelle 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 Rochelle?

Rochelle 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 61068. See growing zones in Illinois.

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