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🍂 First Frost Dates for Lolo, Montana 59847

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 18. (See detailed probabilities below.)

(See also 🌷 Last Spring Frost Dates.)

First frost date probabilities for Lolo, 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% chanceSep 11
20% chanceSep 15
30% chanceSep 18
40% chanceSep 21
50% chanceSep 24
60% chanceSep 26
70% chanceSep 29
80% chanceOct 2
90% chanceOct 5
Probability of moderate freeze (28°F) on or before...
10% chanceSep 22
20% chanceSep 26
30% chanceSep 29
40% chanceOct 1
50% chanceOct 4
60% chanceOct 6
70% chanceOct 9
80% chanceOct 12
90% chanceOct 16
Probability of moderate hard freeze (24°F) on or before...
10% chanceOct 1
20% chanceOct 6
30% chanceOct 10
40% chanceOct 13
50% chanceOct 16
60% chanceOct 19
70% chanceOct 22
80% chanceOct 26
90% chanceOct 31
Probability of hard freeze (20°F) on or before...
10% chanceOct 15
20% chanceOct 20
30% chanceOct 24
40% chanceOct 28
50% chanceOct 31
60% chanceNov 2
70% chanceNov 6
80% chanceNov 11
90% chanceNov 18
Probability of severe hard freeze (16°F) on or before...
10% chanceOct 24
20% chanceOct 31
30% chanceNov 4
40% chanceNov 8
50% chanceNov 12
60% chanceNov 16
70% chanceNov 21
80% chanceNov 26
90% chanceDec 1

Agricultural climatic data from weather station: MISSOULA INTL AP (USW00024153)

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