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🍂 First Frost Dates for Castaic, California 91384

The first 36°F frost date is 30% likely to be on Oct 25. (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 Castaic, 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% chanceOct 11
20% chanceOct 18
30% chanceOct 25
40% chanceOct 31
50% chanceNov 4
60% chanceNov 8
70% chanceNov 13
80% chanceNov 18
90% chanceNov 25
Probability of light freeze (32°F) on or before...
10% chanceOct 29
20% chanceNov 6
30% chanceNov 11
40% chanceNov 17
50% chanceNov 21
60% chanceNov 25
70% chanceNov 30
80% chanceDec 4
90% chanceDec 12
Probability of moderate freeze (28°F) on or before...
10% chanceNov 14
20% chanceNov 22
30% chanceNov 28
40% chanceDec 2
50% chanceDec 7
60% chanceDec 12
70% chanceDec 19
80% chanceDec 27
90% chanceJan 11
Probability of moderate hard freeze (24°F) on or before...
10% chanceNov 28
20% chanceDec 7
30% chanceDec 14
40% chanceDec 22
50% chanceDec 29
60% chanceJan 5
70% chanceJan 17
80% chanceFeb 1
90% chanceFeb 25
Probability of hard freeze (20°F) on or before...
10% chanceDec 11
20% chanceDec 20
30% chanceDec 27
40% chanceJan 1
50% chanceJan 11
60% chanceJan 24
70% chanceFeb 1
80% chanceFeb 17
90% chanceMar 4
Probability of severe hard freeze (16°F) on or before...
10% chanceDec 13
20% chanceDec 19
30% chanceDec 28
40% chanceJan 1
50% chanceJan 7
60% chanceJan 30
70% chanceFeb 5
80% chanceFeb 13
90% chanceFeb 26

Agricultural climatic data from weather station: SANDBERG (USW00023187)

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