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🍂 First Frost Dates for Corwith, Iowa 50430

The first 36°F frost date is 30% likely to be on Sep 20. (See detailed probabilities below.)

The first 32°F light freeze date is 30% likely to be on Sep 27. (See detailed probabilities below.)

(See also 🌷 Last Spring Frost Dates.)

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

Agricultural climatic data from weather station: BRITT (USC00130923)

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