Hillsboro, OR Frost Dates
The last spring frost in Hillsboro usually comes around April 16 and the first fall frost around October 23.
| Spring (last) | Fall (first) | |
|---|---|---|
| Frost, 32°F | April 16 | October 23 |
| Hard freeze, 28°F | March 13 | November 12 |
Growing season: about 191 days.
Frequently asked questions
When is the last frost in Hillsboro, OR?
The median date of the last spring frost (32°F) is April 16. In half of years the last frost comes earlier and in half it comes later, so waiting a week or two past April 16 lowers the risk for tender plants.
When is the first frost in Hillsboro?
The median date of the first fall frost (32°F) is October 23, and a hard freeze (28°F) usually follows around November 12.
How long is the growing season in Hillsboro?
About 191 days between the median last spring frost and first fall frost.
NOAA NCEI U.S. Climate Normals 1991-2020, station USW00094261. Median (50% probability) dates. Low spots and valleys can frost later in spring and earlier in fall than the station.