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Will it freeze in DeKalb in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Fri, Nov 6: 28°F (Fri, Nov 6, 6:00 PM CST to Sat, Nov 7, 6:00 AM CST).
Tonight: forecast low 37°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.
- Tonight 37°F Above 36°F · Areas Of Drizzle then Mostly Cloudy
- Fri, Nov 6 28°F Hard freeze · Mostly Clear
- Sat, Nov 7 32°F Freeze · Mostly Clear
- Sun, Nov 8 34°F Frost possible · Mostly Clear
- Mon, Nov 9 40°F Above 36°F · Mostly Clear
- Tue, Nov 10 37°F Above 36°F · Partly Cloudy
- Wed, Nov 11 38°F Above 36°F · Partly Cloudy
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 DeKalb
The median first fall hard-freeze date (28°F) is October 28, from NOAA’s 1991–2020 Climate Normals at De Kalb. 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 | Apr 20 · May 4 · May 22 | Sep 25 · Oct 7 · Oct 21 | 156 days |
| 32°F freeze | Apr 9 · Apr 24 · May 10 | Oct 4 · Oct 18 · Oct 31 | 177 days |
| 28°F hard freeze | Mar 30 · Apr 13 · Apr 29 | Oct 14 · Oct 28 · Nov 12 | 198 days |
Average high temperature by month
1991–2020 normals at De Kalb
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 DeKalb, IL come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: De Kalb (station USC00112223, elevation 873 ft), 1.5 mi from DeKalb. 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 DeKalb
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Sycamore, IL | 6.2 mi | Apr 24 | Oct 18 |
| Genoa, IL | 12 mi | Apr 24 | Oct 18 |
| Elburn, IL | 15 mi | Apr 28 | Oct 13 |
| Rochelle, IL | 16 mi | Apr 26 | Oct 13 |
| Campton Hills, IL | 17 mi | Apr 25 | Oct 19 |
| Hampshire, IL | 18 mi | Apr 28 | Oct 12 |
| Sugar Grove, IL | 19 mi | Apr 28 | Oct 13 |
| Pingree Grove, IL | 19 mi | Apr 26 | Oct 18 |
| Plano, IL | 21 mi | Apr 28 | Oct 13 |
| Sandwich, IL | 21 mi | Apr 28 | Oct 13 |
Frequently asked questions
When is the last frost in DeKalb?
On average, the last spring frost (32°F) in DeKalb is around April 24. In about 1 year in 10 it comes after May 10, and in 9 years in 10 it comes after April 9.
When is the first frost in DeKalb?
The first fall frost (32°F) usually arrives around October 18. There’s a 10% chance of a freeze by October 4 and a 90% chance by October 31.
Can it frost in DeKalb 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 4.
What growing zone is DeKalb?
DeKalb 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 60115. See growing zones in Illinois.
More: all Illinois frost dates · Illinois growing zones · UV index today in DeKalb · frost vs. freeze