The last 36°F Spring frost date is 30% likely to be on May 17. (See detailed probabilities below.)
The last 32°F light freeze date is 30% likely to be on Apr 28. (See detailed probabilities below.)
(See also 🍂 First Fall Frost Dates.)
Last frost date probabilities for Hillsboro, OR are based on historical climate data.
Always check your local forecast for the most up-to-date frost warnings.
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The last spring frost signals when your area is safe from freezing temperatures. Tender plants can now grow outdoors without cold damage! This marks the beginning of the growing season. Last spring frost serves as your essential starting point for planting warm-season crops. It's also time to remove winter protection from your perennials. Enjoy the longer days and warmer weather!
Start seeds indoors several weeks before your last frost date. This gives plants time to reach transplanting size when weather permits. Plan your outdoor planting schedule around your area's average last frost date. Plant some crops before and some after this date to protect against weather changes. Look for spots in your yard where frost stays longer or disappears earlier. Create your own frost map to use all available growing space and extend your season. Keep watching your local weather forecast to catch any surprise late frosts.
| Probability of frost (36°F) on or after… | |
|---|---|
| 10% chance | May 29 |
| 20% chance | May 23 |
| 30% chance | May 17 |
| 40% chance | May 13 |
| 50% chance | May 9 |
| 60% chance | May 5 |
| 70% chance | May 1 |
| 80% chance | Apr 28 |
| 90% chance | Apr 22 |
| Probability of light freeze (32°F) on or after… | |
|---|---|
| 10% chance | May 8 |
| 20% chance | May 2 |
| 30% chance | Apr 28 |
| 40% chance | Apr 23 |
| 50% chance | Apr 18 |
| 60% chance | Apr 13 |
| 70% chance | Apr 7 |
| 80% chance | Mar 31 |
| 90% chance | Mar 24 |
| Probability of moderate freeze (28°F) on or after… | |
|---|---|
| 10% chance | Apr 13 |
| 20% chance | Apr 1 |
| 30% chance | Mar 26 |
| 40% chance | Mar 21 |
| 50% chance | Mar 14 |
| 60% chance | Mar 6 |
| 70% chance | Feb 27 |
| 80% chance | Feb 21 |
| 90% chance | Feb 9 |
| Probability of moderate hard freeze (24°F) on or after… | |
|---|---|
| 10% chance | Mar 7 |
| 20% chance | Feb 27 |
| 30% chance | Feb 21 |
| 40% chance | Feb 16 |
| 50% chance | Feb 9 |
| 60% chance | Feb 2 |
| 70% chance | Jan 25 |
| 80% chance | Jan 12 |
| 90% chance | Jan 1 |
| Probability of hard freeze (20°F) on or after… | |
|---|---|
| 10% chance | Feb 20 |
| 20% chance | Feb 12 |
| 30% chance | Feb 5 |
| 40% chance | Jan 31 |
| 50% chance | Jan 19 |
| 60% chance | Jan 7 |
| 70% chance | Jan 1 |
| 80% chance | Dec 24 |
| 90% chance | Dec 10 |
| Probability of severe hard freeze (16°F) on or after… | |
|---|---|
| 10% chance | Feb 15 |
| 20% chance | Feb 6 |
| 30% chance | Jan 31 |
| 40% chance | Jan 11 |
| 50% chance | Jan 3 |
| 60% chance | Dec 31 |
| 70% chance | Dec 25 |
| 80% chance | Dec 16 |
| 90% chance | Dec 7 |
Agricultural climatic data from weather station: PORTLAND-HILLSBORO AP (USW00094261)