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🍂 First Frost Dates for Alberton, Montana 59820

The first 36°F frost date is 30% likely to be on Sep 5. (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 Alberton, MT 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 29
20% chanceSep 2
30% chanceSep 5
40% chanceSep 8
50% chanceSep 11
60% chanceSep 13
70% chanceSep 16
80% chanceSep 19
90% chanceSep 24
Probability of light freeze (32°F) on or before...
10% chanceSep 9
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 21
20% chanceSep 27
30% chanceOct 1
40% chanceOct 3
50% chanceOct 5
60% chanceOct 8
70% chanceOct 12
80% chanceOct 16
90% chanceOct 22
Probability of moderate hard freeze (24°F) on or before...
10% chanceOct 2
20% chanceOct 8
30% chanceOct 13
40% chanceOct 18
50% chanceOct 22
60% chanceOct 26
70% chanceOct 30
80% chanceNov 3
90% chanceNov 9
Probability of hard freeze (20°F) on or before...
10% chanceOct 16
20% chanceOct 24
30% chanceOct 30
40% chanceNov 2
50% chanceNov 6
60% chanceNov 10
70% chanceNov 14
80% chanceNov 19
90% chanceNov 26
Probability of severe hard freeze (16°F) on or before...
10% chanceOct 25
20% chanceNov 2
30% chanceNov 8
40% chanceNov 12
50% chanceNov 17
60% chanceNov 23
70% chanceNov 27
80% chanceDec 3
90% chanceDec 10

Agricultural climatic data from weather station: SUPERIOR (USW00024159)

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