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🍂 First Frost Dates for Dewey, Illinois 61840

The first 36°F frost date is 30% likely to be on Oct 1. (See detailed probabilities below.)

The first 32°F light freeze date is 30% likely to be on Oct 11. (See detailed probabilities below.)

(See also 🌷 Last Spring Frost Dates.)

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

Agricultural climatic data from weather station: RANTOUL (USW00014806)

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