September weather in Hillsboro, OR
The average temperature in Hillsboro in September is 62.0°F (47.5°F–76.4°F). Average precipitation: 1.38 inches.
September is a fall month in Hillsboro, and is warmer than the annual average of 52.5°F. Daily temperatures swing about 28.9°F between overnight low and afternoon high. Expect about 8 days with precipitation. Daylight averages about 12h 18m. For travel, September is a comfortable month to visit.
Avg High
76.4°F
Avg Low
47.5°F
Precipitation
1.38 in
Daylight
12h 18m
September records in Hillsboro
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 96.1°F (2017) | 37.9°F (1999) | 0.09 in (2000) |
| September 2 | 100.0°F (2017) | 39.9°F (2012) | 0.49 in (2023) |
| September 3 | 98.1°F (2020) | 42.1°F (1999) | 0.06 in (2000) |
| September 4 | 95.0°F (2003) | 39.0°F (2015) | 0.16 in (2007) |
| September 5 | 100.0°F (2024) | 39.9°F (2000) | 0.77 in (2013) |
| September 6 | 95.0°F (2014) | 37.9°F (2001) | 0.65 in (2013) |
| September 7 | 96.1°F (2011) | 37.0°F (1999) | 0.87 in (2010) |
| September 8 | 90.0°F (2011) | 37.9°F (2002) | 0.28 in (2019) |
| September 9 | 93.0°F (2011) | 39.0°F (2000) | 0.49 in (2003) |
| September 10 | 95.0°F (2011) | 37.9°F (1999) | 0.40 in (2019) |
| September 11 | 97.0°F (2013) | 37.0°F (2012) | 0.39 in (2018) |
| September 12 | 90.0°F (2015) | 42.1°F (2012) | 0.08 in (2018) |
| September 13 | 91.9°F (1999) | 41.0°F (2008) | 0.24 in (2004) |
| September 14 | 91.9°F (2023) | 42.1°F (2014) | 0.26 in (2025) |
| September 15 | 93.9°F (2023) | 39.9°F (2015) | 0.69 in (2019) |
| September 16 | 90.0°F (2008) | 37.0°F (2021) | 0.34 in (2013) |
| September 17 | 91.0°F (2012) | 41.0°F (2018) | 0.45 in (2019) |
| September 18 | 91.0°F (1999) | 36.0°F (2007) | 1.24 in (2021) |
| September 19 | 91.9°F (1999) | 39.0°F (2007) | 0.67 in (2021) |
| September 20 | 93.0°F (2014) | 36.0°F (2001) | 0.40 in (2017) |
| September 21 | 88.0°F (1999) | 39.0°F (2002) | 0.26 in (2025) |
| September 22 | 91.9°F (2009) | 35.1°F (2005) | 0.19 in (2013) |
| September 23 | 88.0°F (2002) | 35.1°F (2000) | 0.64 in (2014) |
| September 24 | 91.0°F (2024) | 32.0°F (2000) | 0.27 in (2013) |
| September 25 | 90.0°F (2022) | 35.1°F (2000) | 0.94 in (2023) |
| September 26 | 90.0°F (2016) | 35.1°F (2000) | 0.30 in (2001) |
| September 27 | 95.0°F (2003) | 30.0°F (1999) | 0.41 in (2021) |
| September 28 | 86.0°F (2006) | 33.1°F (1999) | 1.73 in (2013) |
| September 29 | 89.1°F (2008) | 35.1°F (2007) | 1.39 in (2013) |
| September 30 | 84.9°F (2010) | 34.0°F (2019) | 1.28 in (2005) |