Frost dates 2026–2027

Frost dates for Maryville, Illinois

Median (50% chance) dates of the last and first 32°F frost, from NOAA 1991–2020 climate normals at Alton - Melvin Price L&d, 14 mi away (close match).

Last spring frostApr 4
First fall frostNov 5
214 frost-free days
Last spring frostApr 41 year in 10 after Apr 19
First fall frostNov 51 year in 10 by Oct 25
Growing season214 daysbetween median 32°F dates
Hardiness zoneZone 7a0 to 5°F average extreme low

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Will it freeze in Maryville in the next 7 nights?

No overnight lows at or below 32°F are forecast in Maryville during the next 7 nights in the available NWS frost forecast.

Tonight: forecast low 46°F. Above 36°F.

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

2 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 Maryville

The median first fall hard-freeze date (28°F) is November 16, from NOAA’s 1991–2020 Climate Normals at Alton - Melvin Price L&d. 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 Mar 31 · Apr 14 · May 1 Oct 12 · Oct 27 · Nov 8 192 days
32°F freeze Mar 18 · Apr 4 · Apr 19 Oct 25 · Nov 5 · Nov 21 214 days
28°F hard freeze Mar 6 · Mar 25 · Apr 9 Nov 2 · Nov 16 · Dec 1 237 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USC00110137. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Alton - Melvin Price L&d

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 Maryville, IL come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Alton - Melvin Price L&d (station USC00110137, elevation 405 ft), 14 mi from Maryville. 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 Maryville

CityDistanceLast spring frostFirst fall frost
Glen Carbon, IL 2.5 mi Apr 4 Nov 5
Troy, IL 3.7 mi Apr 12 Oct 20
Collinsville, IL 4.3 mi Apr 8 Oct 26
Edwardsville, IL 4.3 mi Apr 4 Nov 5
Pontoon Beach, IL 5.0 mi Apr 4 Nov 5
Granite City, IL 8.7 mi Apr 4 Nov 5
O'Fallon, IL 9.3 mi Apr 12 Oct 20
Fairview Heights, IL 9.3 mi Apr 8 Oct 26
Wood River, IL 11 mi Apr 4 Nov 5
East St. Louis, IL 12 mi Apr 8 Oct 26

Frequently asked questions

When is the last frost in Maryville?

On average, the last spring frost (32°F) in Maryville is around April 4. In about 1 year in 10 it comes after April 19, and in 9 years in 10 it comes after March 18.

When is the first frost in Maryville?

The first fall frost (32°F) usually arrives around November 5. There’s a 10% chance of a freeze by October 25 and a 90% chance by November 21.

Can it frost in Maryville 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 April 14.

What growing zone is Maryville?

Maryville is in USDA Plant Hardiness Zone 7a (average annual extreme minimum temperature 0 to 5°F), based on the 2023 USDA map for ZIP code 62062. See growing zones in Illinois.

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