๐Ÿ‚ First Frost Dates for Bismarck, North Dakota 58501

The first 36ยฐF frost date is 30% likely to be on Sep 9. (See detailed probabilities below.)

The first 32ยฐF light freeze date is 30% likely to be on Sep 19. (See detailed probabilities below.)

(See also ๐ŸŒท Last Spring Frost Dates.)

First frost date probabilities for Bismarck, ND are based on historical climate data.

Always check your local forecast for the most up-to-date frost warnings.

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 sweaterโ€”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 (36ยฐF) on or before...
10% chanceAug 31
20% chanceSep 6
30% chanceSep 9
40% chanceSep 12
50% chanceSep 15
60% chanceSep 17
70% chanceSep 20
80% chanceSep 23
90% chanceSep 26
Probability of light freeze (32ยฐF) on or before...
10% chanceSep 12
20% chanceSep 16
30% chanceSep 19
40% chanceSep 21
50% chanceSep 24
60% chanceSep 26
70% chanceSep 29
80% chanceOct 2
90% chanceOct 6
Probability of moderate freeze (28ยฐF) on or before...
10% chanceSep 20
20% chanceSep 24
30% chanceSep 27
40% chanceSep 30
50% chanceOct 2
60% chanceOct 4
70% chanceOct 7
80% chanceOct 11
90% chanceOct 16
Probability of moderate hard freeze (24ยฐF) on or before...
10% chanceSep 28
20% chanceOct 2
30% chanceOct 5
40% chanceOct 8
50% chanceOct 11
60% chanceOct 14
70% chanceOct 17
80% chanceOct 21
90% chanceOct 25
Probability of hard freeze (20ยฐF) on or before...
10% chanceOct 6
20% chanceOct 11
30% chanceOct 14
40% chanceOct 18
50% chanceOct 21
60% chanceOct 24
70% chanceOct 27
80% chanceOct 31
90% chanceNov 5
Probability of severe hard freeze (16ยฐF) on or before...
10% chanceOct 14
20% chanceOct 20
30% chanceOct 24
40% chanceOct 28
50% chanceNov 1
60% chanceNov 3
70% chanceNov 6
80% chanceNov 10
90% chanceNov 15

Agricultural climatic data from weather station: BISMARCK (USW00024011)