September is one of the warmer months of the year in Doylestown, with average highs near 25.3°C and lows around 13.2°C (mean 19.3°C). It is about average for rainfall, averaging 110 mm of rainfall and 73% relative humidity across the period.
September is one of the warmer months of the year in Doylestown. Across 45 years of records, the warmest September in Doylestown was 2005 — when the month averaged 22.1°C — while the coldest was 1984 at 16.1°C. Typical September days reach 25.3°C with nights near 13.2°C. The long-term trend is warming, about 0.6°C per decade.
September is about average for rainfall in Doylestown, averaging 110 mm of rainfall. The wettest September on record was 2011 with 258 mm, while the driest was 2019 at 21 mm.
Relative humidity in Doylestown during September averages 73%. The most humid September was 2011 at 87%, and the least humid was 2005 at 60%.
September receives about 4.2 kWh/m²/day of solar energy in Doylestown. The sunniest September was 2007 at 5 kWh/m²/day, and the cloudiest was 2018 at 3.1.
Average wind speed in Doylestown during September is 0.1 m/s. The windiest Septembers were 1982 and 2016 at 0.2 m/s, while the calmest were 2023, 2024 and 2025, among others at 0.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 18.3°C | 18.6°C | 19.3°C | 20.3°C | 20.1°C | +1.8°C |
| Avg High | 24.6°C | 24.6°C | 25.3°C | 26.3°C | 25.9°C | +1.3°C |
| Avg Low | 12.0°C | 12.5°C | 13.2°C | 14.2°C | 14.3°C | +2.3°C |
| Avg Rain | 102 mm | 115 mm | 114 mm | 108 mm | 107 mm | +5 mm |
September temperatures in Doylestown have risen by about 1.8°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 1.9°C (1989) to a record high of 36.4°C (2010).
Rainfall in September is about average for rainfall, averaging 110 mm, with a wettest year of 258 mm.
One of the best times to visit Doylestown
September is one of the best times to visit Doylestown. Expect days averaging 25.3°C and nights around 13.2°C (mean 19.3°C) — warmer than Doylestown's yearly average — with higher rainfall (110 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 27.5°C | 21.2°C | 14.8°C | 31.4°C | 10.4°C | 60 mm | 69% | 0.1 m/s | 4.4 |
| 2024 | 26.1°C | 20.2°C | 14.2°C | 30.5°C | 8.7°C | 34 mm | 73% | 0.1 m/s | 4.1 |
| 2023 | 25.8°C | 20.3°C | 14.8°C | 35.7°C | 9.4°C | 161 mm | 77% | 0.1 m/s | 4.1 |
| 2022 | 26.0°C | 20.0°C | 13.9°C | 31.6°C | 5.2°C | 89 mm | 71% | 0.1 m/s | 4.3 |
| 2021 | 24.5°C | 19.6°C | 14.7°C | 28.9°C | 8.6°C | 205 mm | 83% | 0.1 m/s | 4.2 |
| 2020 | 25.2°C | 19.2°C | 13.1°C | 30.6°C | 4.6°C | 93 mm | 73% | 0.1 m/s | 4.1 |
| 2019 | 27.8°C | 21.1°C | 14.4°C | 33.2°C | 7.2°C | 21 mm | 67% | 0.1 m/s | 4.3 |
| 2018 | 25.3°C | 20.7°C | 16.2°C | 33.5°C | 9.0°C | 199 mm | 87% | 0.1 m/s | 3.1 |
| 2017 | 26.3°C | 20.3°C | 14.3°C | 33.9°C | 8.1°C | 61 mm | 73% | 0.1 m/s | 4.4 |
| 2016 | 27.8°C | 21.3°C | 14.8°C | 35.2°C | 7.6°C | 90 mm | 66% | 0.2 m/s | 4.5 |
| 2015 | 28.1°C | 21.5°C | 14.9°C | 35.7°C | 10.5°C | 100 mm | 69% | 0.1 m/s | 4.5 |
| 2014 | 26.4°C | 20.0°C | 13.6°C | 33.4°C | 6.3°C | 38 mm | 68% | 0.1 m/s | 4.4 |
| 2013 | 24.7°C | 17.8°C | 10.9°C | 33.7°C | 4.0°C | 58 mm | 71% | 0.1 m/s | 4.9 |
| 2012 | 24.9°C | 19.1°C | 13.2°C | 33.7°C | 5.8°C | 129 mm | 76% | 0.1 m/s | 4.2 |
| 2011 🌧️ | 24.5°C | 19.8°C | 15.1°C | 28.8°C | 5.6°C | 258 mm | 87% | 0.1 m/s | 3.2 |
| 2010 | 27.5°C | 20.9°C | 14.3°C | 36.4°C | 7.7°C | 123 mm | 64% | 0.1 m/s | 4.5 |
| 2009 | 22.8°C | 17.5°C | 12.3°C | 28.0°C | 5.7°C | 86 mm | 80% | 0.1 m/s | 4 |
| 2008 | 25.7°C | 19.8°C | 13.9°C | 34.6°C | 6.5°C | 169 mm | 75% | 0.1 m/s | 4.3 |
| 2007 | 27.7°C | 20.7°C | 13.8°C | 32.8°C | 6.6°C | 23 mm | 67% | 0.1 m/s | 5 |
| 2006 | 22.7°C | 17.5°C | 12.3°C | 27.2°C | 5.7°C | 140 mm | 82% | 0.1 m/s | 3.6 |
| 2005 🔥 | 29.4°C | 22.1°C | 14.9°C | 35.0°C | 6.2°C | 33 mm | 60% | 0.1 m/s | 4.9 |
| 2004 | 25.3°C | 19.8°C | 14.2°C | 29.6°C | 6.5°C | 204 mm | 81% | 0.1 m/s | 4 |
| 2003 | 23.6°C | 18.7°C | 13.9°C | 27.3°C | 6.8°C | 188 mm | 84% | 0.1 m/s | 3.7 |
| 2002 | 27.1°C | 20.4°C | 13.7°C | 35.1°C | 8.9°C | 103 mm | 67% | 0.1 m/s | 4.5 |
| 2001 | 25.4°C | 18.4°C | 11.5°C | 31.2°C | 5.3°C | 89 mm | 67% | 0.1 m/s | 4.6 |
| 2000 | 23.8°C | 17.6°C | 11.4°C | 31.3°C | 2.6°C | 109 mm | 75% | 0.1 m/s | 4.1 |
| 1999 | 24.5°C | 18.9°C | 13.3°C | 31.8°C | 5.5°C | 257 mm | 78% | 0.1 m/s | 4 |
| 1998 | 27.1°C | 20.3°C | 13.4°C | 32.6°C | 4.3°C | 60 mm | 67% | 0.1 m/s | 4.3 |
| 1997 | 24.2°C | 18.0°C | 11.9°C | 30.3°C | 4.1°C | 69 mm | 71% | 0.1 m/s | 4.2 |
| 1996 | 24.2°C | 18.8°C | 13.5°C | 31.6°C | 6.0°C | 142 mm | 79% | 0.1 m/s | 3.7 |
| 1995 | 25.0°C | 18.5°C | 12.0°C | 32.5°C | 5.2°C | 111 mm | 65% | 0.1 m/s | 4.3 |
| 1994 | 23.7°C | 17.7°C | 11.6°C | 29.3°C | 7.0°C | 74 mm | 74% | 0.1 m/s | 4.2 |
| 1993 | 24.0°C | 18.6°C | 13.2°C | 32.9°C | 2.9°C | 174 mm | 77% | 0.1 m/s | 3.3 |
| 1992 | 24.2°C | 18.3°C | 12.5°C | 30.2°C | 3.3°C | 97 mm | 74% | 0.1 m/s | 3.8 |
| 1991 | 25.1°C | 18.7°C | 12.2°C | 34.4°C | 2.7°C | 105 mm | 67% | 0.1 m/s | 4.3 |
| 1990 | 24.1°C | 17.8°C | 11.5°C | 31.5°C | 3.1°C | 60 mm | 73% | 0.1 m/s | 4.2 |
| 1989 | 24.3°C | 18.6°C | 13.0°C | 33.8°C | 1.9°C | 186 mm | 78% | 0.1 m/s | 3.9 |
| 1988 | 24.0°C | 17.5°C | 10.9°C | 28.7°C | 5.1°C | 75 mm | 73% | 0.1 m/s | 4.4 |
| 1987 | 23.3°C | 18.0°C | 12.6°C | 27.5°C | 5.1°C | 154 mm | 83% | 0.1 m/s | 3.9 |
| 1986 | 24.8°C | 18.5°C | 12.3°C | 30.5°C | 3.6°C | 66 mm | 73% | 0.1 m/s | 3.9 |
| 1985 | 26.2°C | 19.7°C | 13.1°C | 33.5°C | 5.8°C | 160 mm | 68% | 0.1 m/s | 4.5 |
| 1984 ❄️ | 22.5°C | 16.1°C | 9.7°C | 28.9°C | 4.1°C | 50 mm | 75% | 0.1 m/s | 4.5 |
| 1983 | 27.0°C | 19.8°C | 12.6°C | 35.8°C | 4.5°C | 71 mm | 61% | 0.1 m/s | — |
| 1982 | 25.3°C | 18.7°C | 12.1°C | 31.5°C | 8.1°C | 68 mm | 69% | 0.2 m/s | — |
| 1981 | 24.2°C | 18.1°C | 12.0°C | 31.7°C | 4.6°C | 89 mm | 70% | 0.1 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 25.3°C with lows near 13.2°C (mean 19.3°C), based on 45 years of NASA POWER data.
September averages 110 mm of rainfall in Doylestown, about average for rainfall. The wettest on record was 258 mm in 2011.
The hottest September reached 36.4°C in 2010. The coldest dipped to 1.9°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.8°C. Daytime highs moved from 25°C to 26°C and overnight lows from 11.9°C to 14.5°C over the same span.
September is one of the warmer months of the year in Doylestown and about average for rainfall, so plan for around 25.3°C daytime highs and 13.2°C at night.
Not quite — September is the 9th coolest month in Doylestown, averaging 19.3°C.
For September in Doylestown, pack light layers you can adjust through the day, with typical highs of 25.3°C and lows of 13.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 73% — moderately humid.
Average wind speed in September is 0.1 m/s. The windiest September on record averaged 0.2 m/s (1982).
The wettest September on record was 2011 with 258 mm. On average, September sees 110 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Doylestown behaves each September, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for September specifically, along with year-by-year records and how the month has changed over the decades.
