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🍂 First Frost Dates for Petersburg, Illinois 62675

The first 36°F frost date is 30% likely to be on Sep 27. (See detailed probabilities below.)

The first 32°F light freeze date is 30% likely to be on Oct 6. (See detailed probabilities below.)

(See also 🌷 Last Spring Frost Dates.)

First frost date probabilities for Petersburg, 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% chanceSep 19
20% chanceSep 24
30% chanceSep 27
40% chanceSep 30
50% chanceOct 3
60% chanceOct 5
70% chanceOct 8
80% chanceOct 12
90% chanceOct 18
Probability of light freeze (32°F) on or before...
10% chanceSep 28
20% chanceOct 2
30% chanceOct 6
40% chanceOct 11
50% chanceOct 14
60% chanceOct 18
70% chanceOct 21
80% chanceOct 25
90% chanceOct 30
Probability of moderate freeze (28°F) on or before...
10% chanceOct 8
20% chanceOct 15
30% chanceOct 20
40% chanceOct 24
50% chanceOct 28
60% chanceOct 31
70% chanceNov 3
80% chanceNov 7
90% chanceNov 13
Probability of moderate hard freeze (24°F) on or before...
10% chanceOct 22
20% chanceOct 29
30% chanceNov 1
40% chanceNov 5
50% chanceNov 9
60% chanceNov 13
70% chanceNov 17
80% chanceNov 22
90% chanceNov 28
Probability of hard freeze (20°F) on or before...
10% chanceNov 2
20% chanceNov 9
30% chanceNov 14
40% chanceNov 18
50% chanceNov 23
60% chanceNov 26
70% chanceNov 30
80% chanceDec 4
90% chanceDec 9
Probability of severe hard freeze (16°F) on or before...
10% chanceNov 15
20% chanceNov 22
30% chanceNov 26
40% chanceNov 30
50% chanceDec 3
60% chanceDec 6
70% chanceDec 9
80% chanceDec 13
90% chanceDec 19

Agricultural climatic data from weather station: ATHENS 2SW (USC00110306)

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