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🍂 First Frost Dates for Prospect, Oregon 97536

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 20. (See detailed probabilities below.)

(See also 🌷 Last Spring Frost Dates.)

First frost date probabilities for Prospect, OR 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 12
20% chanceSep 16
30% chanceSep 20
40% chanceSep 24
50% chanceSep 28
60% chanceOct 1
70% chanceOct 5
80% chanceOct 9
90% chanceOct 15
Probability of moderate freeze (28°F) on or before...
10% chanceSep 30
20% chanceOct 5
30% chanceOct 11
40% chanceOct 16
50% chanceOct 20
60% chanceOct 25
70% chanceOct 30
80% chanceNov 3
90% chanceNov 12
Probability of moderate hard freeze (24°F) on or before...
10% chanceOct 23
20% chanceNov 1
30% chanceNov 5
40% chanceNov 10
50% chanceNov 16
60% chanceNov 23
70% chanceDec 1
80% chanceDec 6
90% chanceDec 15
Probability of hard freeze (20°F) on or before...
10% chanceNov 10
20% chanceNov 20
30% chanceNov 30
40% chanceDec 5
50% chanceDec 11
60% chanceDec 16
70% chanceDec 23
80% chanceDec 31
90% chanceJan 13
Probability of severe hard freeze (16°F) on or before...
10% chanceNov 28
20% chanceDec 7
30% chanceDec 14
40% chanceDec 22
50% chanceDec 28
60% chanceJan 2
70% chanceJan 9
80% chanceJan 20
90% chanceFeb 3

Agricultural climatic data from weather station: PROSPECT 2 SW (USC00356907)

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