Last frost date in Hillsboro, Oregon
April 16
Average last frost in spring. In an early year (1 in 10) it's over by March 25; in a late year (1 in 10) it comes after May 3.
October 23
Average first frost in fall. 1 year in 10 it comes by October 3.
Source: NOAA U.S. Climate Normals 1991–2020, station Portland-hillsboro AP (USW00094261), 1.1 miles from Hillsboro, elevation 204 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | Mar 25 | Apr 16 | May 3 |
| First frost in fall | Oct 3 | Oct 23 | Nov 18 |
Frost-free days in an average year: 191
| Chance in a year | Average last in spring | Average first in fall | |
|---|---|---|---|
| Light frost (36°F) | Every year | May 5 | Oct 6 |
| Frost (32°F) | Every year | Apr 16 | Oct 23 |
| Hard freeze (28°F) | Every year | Mar 13 | Nov 12 |
Nights at 32°F or colder in an average year: 64
What to plant now in Hillsboro
- Spring planting calendar for an average last frost around April 20 Hillsboro: April 16
- Fall planting calendar for an average first frost around October 20 Hillsboro: October 23
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5. How we match the table.
Nearby in Oregon
- Beaverton 7 mi · last frost Apr 1
- Forest Grove 8 mi · last frost Apr 16
- Lake Oswego 14 mi · last frost Mar 18
- Portland 14 mi · last frost Feb 25
- Newberg 15 mi · last frost Mar 21
Updated