🍂 2026 First Frost Dates for Philadelphia, Pennsylvania 19120
The first 36°F frost date is 30% likely to be on Oct 31. (See detailed probabilities below.)
The first 32°F light freeze date is 30% likely to be on Nov 11. (See detailed probabilities below.)
(See also 🌷 Last Spring Frost Dates.)
First frost date probabilities for Philadelphia, PA are based on historical climate data.
Always check your local forecast for the most up-to-date frost warnings.
Book Recommendations (ads!)
📚 Growing Under Cover: Techniques for a More Productive, Weather-Resistant, Pest-Free Vegetable Garden
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 23 |
| 20% chance | Oct 28 |
| 30% chance | Oct 31 |
| 40% chance | Nov 3 |
| 50% chance | Nov 5 |
| 60% chance | Nov 8 |
| 70% chance | Nov 11 |
| 80% chance | Nov 15 |
| 90% chance | Nov 20 |
| Probability of light freeze (32°F) on or before... | |
|---|---|
| 10% chance | Nov 4 |
| 20% chance | Nov 8 |
| 30% chance | Nov 11 |
| 40% chance | Nov 14 |
| 50% chance | Nov 17 |
| 60% chance | Nov 20 |
| 70% chance | Nov 23 |
| 80% chance | Nov 28 |
| 90% chance | Dec 4 |
| Probability of moderate freeze (28°F) on or before... | |
|---|---|
| 10% chance | Nov 12 |
| 20% chance | Nov 17 |
| 30% chance | Nov 21 |
| 40% chance | Nov 26 |
| 50% chance | Nov 29 |
| 60% chance | Dec 2 |
| 70% chance | Dec 6 |
| 80% chance | Dec 11 |
| 90% chance | Dec 18 |
| Probability of moderate hard freeze (24°F) on or before... | |
|---|---|
| 10% chance | Nov 24 |
| 20% chance | Dec 1 |
| 30% chance | Dec 5 |
| 40% chance | Dec 9 |
| 50% chance | Dec 14 |
| 60% chance | Dec 19 |
| 70% chance | Dec 22 |
| 80% chance | Dec 27 |
| 90% chance | Jan 2 |
| Probability of hard freeze (20°F) on or before... | |
|---|---|
| 10% chance | Dec 7 |
| 20% chance | Dec 13 |
| 30% chance | Dec 19 |
| 40% chance | Dec 23 |
| 50% chance | Dec 27 |
| 60% chance | Dec 31 |
| 70% chance | Jan 4 |
| 80% chance | Jan 9 |
| 90% chance | Jan 16 |
| Probability of severe hard freeze (16°F) on or before... | |
|---|---|
| 10% chance | Dec 19 |
| 20% chance | Dec 28 |
| 30% chance | Jan 1 |
| 40% chance | Jan 5 |
| 50% chance | Jan 9 |
| 60% chance | Jan 13 |
| 70% chance | Jan 17 |
| 80% chance | Jan 23 |
| 90% chance | Feb 1 |
Agricultural climatic data from weather station: PHILA FRANKLIN INST (USC00366886:frost)