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🍂 First Frost Dates for Phoenix, Arizona 85042

The first 36°F frost date is 30% likely to be on Nov 21. (See detailed probabilities below.)

The first 32°F light freeze date is 30% likely to be on Dec 3. (See detailed probabilities below.)

(See also 🌷 Last Spring Frost Dates.)

First frost date probabilities for Phoenix, AZ 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% chanceNov 12
20% chanceNov 17
30% chanceNov 21
40% chanceNov 24
50% chanceNov 28
60% chanceDec 1
70% chanceDec 4
80% chanceDec 7
90% chanceDec 12
Probability of light freeze (32°F) on or before...
10% chanceNov 24
20% chanceDec 1
30% chanceDec 3
40% chanceDec 7
50% chanceDec 10
60% chanceDec 14
70% chanceDec 18
80% chanceDec 23
90% chanceDec 31
Probability of moderate freeze (28°F) on or before...
10% chanceDec 6
20% chanceDec 13
30% chanceDec 17
40% chanceDec 21
50% chanceDec 26
60% chanceDec 29
70% chanceJan 2
80% chanceJan 8
90% chanceJan 22
Probability of moderate hard freeze (24°F) on or before...
10% chanceDec 14
20% chanceDec 22
30% chanceDec 27
40% chanceDec 29
50% chanceDec 31
60% chanceJan 4
70% chanceJan 6
80% chanceJan 9
90% chanceJan 17
Probability of hard freeze (20°F) on or before...
10% chancerarely
20% chancerarely
30% chancerarely
40% chancerarely
50% chancerarely
60% chancerarely
70% chancerarely
80% chancerarely
90% chancerarely
Probability of severe hard freeze (16°F) on or before...
10% chancerarely
20% chancerarely
30% chancerarely
40% chancerarely
50% chancerarely
60% chancerarely
70% chancerarely
80% chancerarely
90% chancerarely

Agricultural climatic data from weather station: SOUTH PHOENIX (USC00028112)

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