September weather in Plainfield, IN
The average temperature in Plainfield in September is 67.8°F (57.3°F–78.3°F). Average precipitation: 3.45 inches.
September is a fall month in Plainfield, and is warmer than the annual average of 53.3°F. Daily temperatures swing about 21°F between overnight low and afternoon high. Daylight averages about 12h 15m. For travel, September is one of the best months of the year to visit.
Avg High
78.3°F
Avg Low
57.3°F
Precipitation
3.45 in
Daylight
12h 15m
September records in Plainfield
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 99.0°F (2011) | 55.0°F (2025) | 0.20 in (2012) |
| September 2 | 99.0°F (2011) | 54.0°F (2017) | 1.55 in (2012) |
| September 3 | 100.0°F (2011) | 55.9°F (2013) | 0.26 in (2025) |
| September 4 | 95.0°F (2015) | 54.0°F (2025) | 0.24 in (2025) |
| September 5 | 95.0°F (2018) | 52.0°F (2020) | 0.04 in (2012) |
| September 6 | 93.9°F (2015) | 48.9°F (2017) | 0.06 in (2014) |
| September 7 | 93.9°F (2015) | 46.9°F (2017) | 2.86 in (2012) |
| September 8 | 91.9°F (2015) | 44.1°F (2024) | 1.86 in (2018) |
| September 9 | 93.9°F (2013) | 45.0°F (2024) | 0.95 in (2016) |
| September 10 | 99.0°F (2013) | 48.9°F (2017) | 0.77 in (2014) |
| September 11 | 99.0°F (2013) | 50.0°F (2017) | 0.79 in (2022) |
| September 12 | 91.9°F (2019) | 51.1°F (2015) | 0.26 in (2013) |
| September 13 | 91.9°F (2011) | 46.9°F (2014) | 0.22 in (2025) |
| September 14 | 88.0°F (2024) | 45.0°F (2014) | 0.29 in (2011) |
| September 15 | 89.1°F (2025) | 46.0°F (2011) | 0.56 in (2014) |
| September 16 | 89.1°F (2016) | 45.0°F (2011) | 0.52 in (2016) |
| September 17 | 91.0°F (2017) | 45.0°F (2014) | 0.95 in (2016) |
| September 18 | 90.0°F (2018) | 46.9°F (2012) | 0.43 in (2017) |
| September 19 | 89.1°F (2018) | 41.0°F (2012) | 1.88 in (2011) |
| September 20 | 91.9°F (2018) | 46.0°F (2020) | 0.49 in (2013) |
| September 21 | 91.9°F (2017) | 48.9°F (2012) | 1.06 in (2012) |
| September 22 | 93.0°F (2017) | 43.0°F (2012) | 0.53 in (2025) |
| September 23 | 91.0°F (2017) | 39.0°F (2012) | 0.32 in (2019) |
| September 24 | 91.9°F (2017) | 39.0°F (2012) | 0.34 in (2022) |
| September 25 | 91.0°F (2017) | 52.0°F (2012) | 2.17 in (2011) |
| September 26 | 93.0°F (2017) | 50.0°F (2022) | 0.91 in (2016) |
| September 27 | 90.0°F (2019) | 43.0°F (2022) | 1.62 in (2023) |
| September 28 | 88.0°F (2019) | 43.0°F (2022) | 0.79 in (2016) |
| September 29 | 88.0°F (2025) | 43.0°F (2022) | 0.54 in (2013) |
| September 30 | 91.0°F (2019) | 44.1°F (2022) | 0.20 in (2016) |