🍂 2026 First Frost Dates for San Bernardino, California 92404
The first 36°F frost date is 30% likely to be on Oct 10. (See detailed probabilities below.)
The first 32°F light freeze date is 30% likely to be on Oct 25. (See detailed probabilities below.)
(See also 🌷 Last Spring Frost Dates.)
First frost date probabilities for San Bernardino, CA 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 | Sep 30 |
| 20% chance | Oct 5 |
| 30% chance | Oct 10 |
| 40% chance | Oct 13 |
| 50% chance | Oct 18 |
| 60% chance | Oct 23 |
| 70% chance | Oct 28 |
| 80% chance | Nov 1 |
| 90% chance | Nov 5 |
| Probability of light freeze (32°F) on or before... | |
|---|---|
| 10% chance | Oct 12 |
| 20% chance | Oct 19 |
| 30% chance | Oct 25 |
| 40% chance | Oct 30 |
| 50% chance | Nov 2 |
| 60% chance | Nov 5 |
| 70% chance | Nov 8 |
| 80% chance | Nov 11 |
| 90% chance | Nov 15 |
| Probability of moderate freeze (28°F) on or before... | |
|---|---|
| 10% chance | Oct 31 |
| 20% chance | Nov 5 |
| 30% chance | Nov 10 |
| 40% chance | Nov 13 |
| 50% chance | Nov 16 |
| 60% chance | Nov 19 |
| 70% chance | Nov 22 |
| 80% chance | Nov 25 |
| 90% chance | Nov 30 |
| Probability of moderate hard freeze (24°F) on or before... | |
|---|---|
| 10% chance | Nov 13 |
| 20% chance | Nov 20 |
| 30% chance | Nov 24 |
| 40% chance | Nov 27 |
| 50% chance | Dec 1 |
| 60% chance | Dec 4 |
| 70% chance | Dec 8 |
| 80% chance | Dec 13 |
| 90% chance | Dec 21 |
| Probability of hard freeze (20°F) on or before... | |
|---|---|
| 10% chance | Nov 27 |
| 20% chance | Dec 3 |
| 30% chance | Dec 9 |
| 40% chance | Dec 14 |
| 50% chance | Dec 20 |
| 60% chance | Dec 25 |
| 70% chance | Dec 30 |
| 80% chance | Jan 9 |
| 90% chance | Jan 25 |
| Probability of severe hard freeze (16°F) on or before... | |
|---|---|
| 10% chance | Dec 6 |
| 20% chance | Dec 14 |
| 30% chance | Dec 22 |
| 40% chance | Dec 28 |
| 50% chance | Jan 1 |
| 60% chance | Jan 8 |
| 70% chance | Jan 15 |
| 80% chance | Jan 29 |
| 90% chance | Feb 13 |
Agricultural climatic data from weather station: LAKE ARROWHEAD (USC00044671:frost)