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🍂 First Frost Dates for Nampa, Idaho 83651

The first 36°F frost date is 30% likely to be on Sep 21. (See detailed probabilities below.)

The first 32°F light freeze date is 30% likely to be on Oct 3. (See detailed probabilities below.)

(See also 🌷 Last Spring Frost Dates.)

First frost date probabilities for Nampa, 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% chanceSep 12
20% chanceSep 17
30% chanceSep 21
40% chanceSep 24
50% chanceSep 27
60% chanceSep 30
70% chanceOct 2
80% chanceOct 5
90% chanceOct 9
Probability of light freeze (32°F) on or before...
10% chanceSep 25
20% chanceSep 30
30% chanceOct 3
40% chanceOct 5
50% chanceOct 8
60% chanceOct 11
70% chanceOct 15
80% chanceOct 18
90% chanceOct 23
Probability of moderate freeze (28°F) on or before...
10% chanceOct 7
20% chanceOct 12
30% chanceOct 16
40% chanceOct 19
50% chanceOct 22
60% chanceOct 25
70% chanceOct 29
80% chanceNov 1
90% chanceNov 8
Probability of moderate hard freeze (24°F) on or before...
10% chanceOct 21
20% chanceOct 27
30% chanceOct 31
40% chanceNov 3
50% chanceNov 7
60% chanceNov 11
70% chanceNov 15
80% chanceNov 20
90% chanceNov 25
Probability of hard freeze (20°F) on or before...
10% chanceNov 1
20% chanceNov 7
30% chanceNov 13
40% chanceNov 18
50% chanceNov 23
60% chanceNov 26
70% chanceNov 30
80% chanceDec 4
90% chanceDec 11
Probability of severe hard freeze (16°F) on or before...
10% chanceNov 12
20% chanceNov 21
30% chanceNov 26
40% chanceNov 30
50% chanceDec 4
60% chanceDec 8
70% chanceDec 13
80% chanceDec 19
90% chanceDec 29

Agricultural climatic data from weather station: NAMPA SUGAR FACTORY (USC00106305)

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