🍂 2026 First Frost Dates for Shepherd, Montana 59079
The first 36°F frost date is 30% likely to be on Sep 9. (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 Shepherd, 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% chance | Sep 1 |
| 20% chance | Sep 6 |
| 30% chance | Sep 9 |
| 40% chance | Sep 12 |
| 50% chance | Sep 14 |
| 60% chance | Sep 18 |
| 70% chance | Sep 20 |
| 80% chance | Sep 24 |
| 90% chance | Sep 29 |
| Probability of light freeze (32°F) on or before... | |
|---|---|
| 10% chance | Sep 13 |
| 20% chance | Sep 18 |
| 30% chance | Sep 20 |
| 40% chance | Sep 23 |
| 50% chance | Sep 25 |
| 60% chance | Sep 28 |
| 70% chance | Oct 1 |
| 80% chance | Oct 4 |
| 90% chance | Oct 8 |
| Probability of moderate freeze (28°F) on or before... | |
|---|---|
| 10% chance | Sep 23 |
| 20% chance | Sep 26 |
| 30% chance | Sep 29 |
| 40% chance | Oct 2 |
| 50% chance | Oct 4 |
| 60% chance | Oct 7 |
| 70% chance | Oct 11 |
| 80% chance | Oct 14 |
| 90% chance | Oct 18 |
| Probability of moderate hard freeze (24°F) on or before... | |
|---|---|
| 10% chance | Oct 1 |
| 20% chance | Oct 4 |
| 30% chance | Oct 9 |
| 40% chance | Oct 12 |
| 50% chance | Oct 15 |
| 60% chance | Oct 18 |
| 70% chance | Oct 20 |
| 80% chance | Oct 25 |
| 90% chance | Oct 29 |
| Probability of hard freeze (20°F) on or before... | |
|---|---|
| 10% chance | Oct 8 |
| 20% chance | Oct 14 |
| 30% chance | Oct 18 |
| 40% chance | Oct 23 |
| 50% chance | Oct 26 |
| 60% chance | Oct 29 |
| 70% chance | Nov 1 |
| 80% chance | Nov 4 |
| 90% chance | Nov 9 |
| Probability of severe hard freeze (16°F) on or before... | |
|---|---|
| 10% chance | Oct 16 |
| 20% chance | Oct 22 |
| 30% chance | Oct 28 |
| 40% chance | Oct 31 |
| 50% chance | Nov 3 |
| 60% chance | Nov 6 |
| 70% chance | Nov 9 |
| 80% chance | Nov 14 |
| 90% chance | Nov 20 |
Agricultural climatic data from weather station: HUNTLEY EXP STN (USC00244345:frost)