🍂 2026 First Frost Dates for Berwyn, Illinois 60402
The first 36°F frost date is 30% likely to be on Oct 17. (See detailed probabilities below.)
The first 32°F light freeze date is 30% likely to be on Oct 26. (See detailed probabilities below.)
(See also 🌷 Last Spring Frost Dates.)
First frost date probabilities for Berwyn, IL are based on historical climate data.
Always check your local forecast for the most up-to-date frost warnings.
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What is a First Frost Date?
The first fall frost signals the end of your local growing season. This date serves as an important deadline for gardeners and farmers. You'll need to complete harvesting before this point. Annuals and other tender plants will die back when frost hits, and perennial plants will enter their dormant phase for winter. Meanwhile, it's time to enjoy a cup of hot cocoa and a cozy sweater—and start planning your spring garden!
How to use the First Frost Date?
Watch your local weather forecasts in early fall to predict the first frost date. Harvest tender crops and protect vulnerable plants before frost arrives. For late-summer plantings, count backward from your area's average first frost date. This ensures your crops have enough time to mature. Keep track of when frost actually occurs in your garden each year. This helps you identify protected spots where the growing season might last longer.
First Frost Date Probabilities
| Probability of frost (36°F) on or before... | |
|---|---|
| 10% chance | Oct 8 |
| 20% chance | Oct 13 |
| 30% chance | Oct 17 |
| 40% chance | Oct 19 |
| 50% chance | Oct 21 |
| 60% chance | Oct 24 |
| 70% chance | Oct 26 |
| 80% chance | Oct 28 |
| 90% chance | Nov 1 |
| Probability of light freeze (32°F) on or before... | |
|---|---|
| 10% chance | Oct 20 |
| 20% chance | Oct 23 |
| 30% chance | Oct 26 |
| 40% chance | Oct 29 |
| 50% chance | Oct 31 |
| 60% chance | Nov 2 |
| 70% chance | Nov 5 |
| 80% chance | Nov 9 |
| 90% chance | Nov 14 |
| Probability of moderate freeze (28°F) on or before... | |
|---|---|
| 10% chance | Oct 31 |
| 20% chance | Nov 2 |
| 30% chance | Nov 5 |
| 40% chance | Nov 8 |
| 50% chance | Nov 11 |
| 60% chance | Nov 14 |
| 70% chance | Nov 17 |
| 80% chance | Nov 21 |
| 90% chance | Nov 26 |
| Probability of moderate hard freeze (24°F) on or before... | |
|---|---|
| 10% chance | Nov 7 |
| 20% chance | Nov 11 |
| 30% chance | Nov 14 |
| 40% chance | Nov 17 |
| 50% chance | Nov 20 |
| 60% chance | Nov 24 |
| 70% chance | Nov 26 |
| 80% chance | Dec 1 |
| 90% chance | Dec 5 |
| Probability of hard freeze (20°F) on or before... | |
|---|---|
| 10% chance | Nov 13 |
| 20% chance | Nov 18 |
| 30% chance | Nov 22 |
| 40% chance | Nov 26 |
| 50% chance | Nov 29 |
| 60% chance | Dec 1 |
| 70% chance | Dec 5 |
| 80% chance | Dec 10 |
| 90% chance | Dec 18 |
| Probability of severe hard freeze (16°F) on or before... | |
|---|---|
| 10% chance | Nov 22 |
| 20% chance | Nov 27 |
| 30% chance | Dec 1 |
| 40% chance | Dec 3 |
| 50% chance | Dec 7 |
| 60% chance | Dec 11 |
| 70% chance | Dec 15 |
| 80% chance | Dec 21 |
| 90% chance | Dec 26 |
Agricultural climatic data from weather station: CHICAGO MIDWAY AP (USW00014819:frost)