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🍂 First Frost Dates for Idaho Falls, Idaho 83404

The first 36°F frost date is 30% likely to be on Sep 7. (See detailed probabilities below.)

The first 32°F light freeze date is 30% likely to be on Sep 18. (See detailed probabilities below.)

(See also 🌷 Last Spring Frost Dates.)

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

Agricultural climatic data from weather station: IDAHO FALLS - KIFI (USC00104455)

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