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Will it freeze in Glen Carbon in the next 7 nights?
No overnight lows at or below 32°F are forecast in Glen Carbon 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.
- Tonight 46°F Above 36°F · Slight Chance Drizzle then Cloudy
- Fri, Nov 6 33°F Frost possible · Mostly Clear
- Sat, Nov 7 34°F Frost possible · Mostly Clear
- Sun, Nov 8 37°F Above 36°F · Clear
- Mon, Nov 9 42°F Above 36°F · Clear
- Tue, Nov 10 43°F Above 36°F · Mostly Clear
- Wed, Nov 11 43°F Above 36°F · Mostly Clear
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 Glen Carbon
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.
| Temperature | Last 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 |
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 Glen Carbon, 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), 12 mi from Glen Carbon. 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 Glen Carbon
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Edwardsville, IL | 2.5 mi | Apr 4 | Nov 5 |
| Maryville, IL | 2.5 mi | Apr 4 | Nov 5 |
| Pontoon Beach, IL | 5.0 mi | Apr 4 | Nov 5 |
| Troy, IL | 5.6 mi | Apr 12 | Oct 20 |
| Collinsville, IL | 5.6 mi | Apr 8 | Oct 26 |
| Granite City, IL | 8.1 mi | Apr 4 | Nov 5 |
| Wood River, IL | 8.7 mi | Apr 4 | Nov 5 |
| Bethalto, IL | 11 mi | Apr 4 | Nov 5 |
| East Alton, IL | 11 mi | Apr 4 | Nov 5 |
| Fairview Heights, IL | 11 mi | Apr 8 | Oct 26 |
Frequently asked questions
When is the last frost in Glen Carbon?
On average, the last spring frost (32°F) in Glen Carbon 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 Glen Carbon?
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 Glen Carbon 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 Glen Carbon?
Glen Carbon 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 62034. See growing zones in Illinois.
More: all Illinois frost dates · Illinois growing zones · frost vs. freeze