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🍂 First Frost Dates for Fairfield, Montana 59436

A 36°F frost is always a risk here. (See detailed probabilities below.)

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

(See also 🌷 Last Spring Frost Dates.)

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

Agricultural climatic data from weather station: CHOTEAU (USC00241737)

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