Climate
Hillsboro weather by month
Average highs, lows, rain and snow for every month, from 30 years of weather records.
Average temperatures
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
Best time to visit: June, July, August, when highs are mild and rain is lightest.
Month by month
| Month | High | Low | Rain | Wet days |
|---|---|---|---|---|
| January | 47°F | 34°F | 5.3 in | 19 |
| February | 51°F | 34°F | 4.0 in | 16 |
| March | 56°F | 37°F | 3.7 in | 18 |
| April | 61°F | 39°F | 2.6 in | 16 |
| May | 69°F | 45°F | 2.0 in | 12 |
| June | 74°F | 49°F | 1.3 in | 9 |
| July | 82°F | 52°F | 0.40 in | 3 |
| August | 82°F | 52°F | 0.50 in | 4 |
| September | 76°F | 48°F | 1.4 in | 8 |
| October | 64°F | 41°F | 3.4 in | 15 |
| November | 53°F | 37°F | 5.4 in | 19 |
| December | 46°F | 33°F | 6.0 in | 20 |
NOAA U.S. Climate Normals 1991–2020, Portland-Hillsboro Ap, Or Us (1.2 mi away, 204 ft). Wet days: days with at least 0.01 in of precipitation.
Questions
What is the hottest month in Hillsboro?
August, with an average high of 82°F and low of 52°F.
What is the coldest month in Hillsboro?
December, with an average low of 33°F and high of 46°F.
When does it rain most in Hillsboro?
December is the wettest month, averaging 6.0 in of precipitation; the year totals about 36.0 inches.
What is the best time to visit Hillsboro?
For mild weather (highs between 65°F and 85°F) with the least rain, June, July, August.
Where do these numbers come from?
NOAA’s 1991–2020 U.S. Climate Normals for the Portland-Hillsboro Ap weather station, 1.2 miles from downtown: 30-year averages, not a forecast.