September weather in Umatilla, OR
The average temperature in Umatilla in September is 65.7°F (53.4°F–78.0°F). Average precipitation: 0.40 inches.
September is a fall month in Umatilla, and is warmer than the annual average of 53.9°F. Daily temperatures swing about 24.6°F between overnight low and afternoon high. Expect about 3 days with precipitation. Daylight averages about 12h 18m. For travel, September is one of the best months of the year to visit.
Avg High
78.0°F
Avg Low
53.4°F
Precipitation
0.40 in
Daylight
12h 18m
September records in Umatilla
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 99.0°F (2022) | 46.9°F (2021) | 0.09 in (2009) |
| September 2 | 98.1°F (2022) | 39.9°F (2021) | 0.09 in (2009) |
| September 3 | 99.0°F (2025) | 48.9°F (2021) | 0.41 in (2013) |
| September 4 | 98.1°F (2025) | 46.9°F (2008) | 0.00 in (2007) |
| September 5 | 91.0°F (2013) | 50.0°F (2011) | 0.04 in (2007) |
| September 6 | 91.9°F (2020) | 51.1°F (2014) | 0.29 in (2013) |
| September 7 | 93.0°F (2020) | 52.0°F (2010) | 0.25 in (2016) |
| September 8 | 93.0°F (2011) | 51.1°F (2009) | 0.05 in (2023) |
| September 9 | 91.0°F (2021) | 48.0°F (2009) | 0.00 in (2007) |
| September 10 | 90.0°F (2011) | 46.9°F (2020) | 0.10 in (2025) |
| September 11 | 90.0°F (2016) | 48.0°F (2007) | 0.07 in (2021) |
| September 12 | 88.0°F (2007) | 45.0°F (2012) | 0.40 in (2024) |
| September 13 | 90.0°F (2011) | 44.1°F (2012) | 0.00 in (2007) |
| September 14 | 91.9°F (2013) | 46.0°F (2012) | 0.00 in (2007) |
| September 15 | 89.1°F (2013) | 45.0°F (2016) | 0.10 in (2025) |
| September 16 | 91.9°F (2013) | 45.0°F (2021) | 1.00 in (2013) |
| September 17 | 90.0°F (2009) | 46.9°F (2017) | 0.28 in (2019) |
| September 18 | 87.1°F (2023) | 46.9°F (2017) | 0.74 in (2010) |
| September 19 | 84.9°F (2012) | 48.0°F (2018) | 0.13 in (2010) |
| September 20 | 84.9°F (2014) | 42.1°F (2021) | 0.12 in (2017) |
| September 21 | 89.1°F (2025) | 46.0°F (2007) | 0.17 in (2023) |
| September 22 | 79.0°F (2019) | 44.1°F (2017) | 0.10 in (2023) |
| September 23 | 87.1°F (2011) | 44.1°F (2008) | 0.08 in (2013) |
| September 24 | 86.0°F (2024) | 43.0°F (2008) | 0.02 in (2010) |
| September 25 | 84.9°F (2025) | 45.0°F (2007) | 0.03 in (2023) |
| September 26 | 88.0°F (2021) | 46.0°F (2007) | 0.02 in (2023) |
| September 27 | 84.9°F (2009) | 46.0°F (2018) | 0.00 in (2007) |
| September 28 | 84.9°F (2010) | 46.9°F (2008) | 0.41 in (2021) |
| September 29 | 86.0°F (2010) | 42.1°F (2019) | 0.10 in (2007) |
| September 30 | 82.0°F (2012) | 41.0°F (2019) | 0.02 in (2013) |