September is one of the warmer months of the year in Wilkes Barre, with average highs near 23.4°C and lows around 11.4°C (mean 17.4°C). It is a relatively wet time of year, averaging 115 mm of rainfall and 74% relative humidity across the period.
September is one of the warmer months of the year in Wilkes Barre. Across 45 years of records, the warmest September in Wilkes Barre was 2005 — when the month averaged 20°C — while the coldest was 1984 at 14.6°C. Typical September days reach 23.4°C with nights near 11.4°C. The long-term trend is warming, about 0.5°C per decade.
September is a relatively wet time of year in Wilkes Barre, averaging 115 mm of rainfall. The wettest September on record was 2011 with 336 mm, while the driest was 2019 at 21 mm.
Relative humidity in Wilkes Barre during September averages 74%. The most humid September was 2011 at 88%, and the least humid was 1983 at 60%.
September receives about 4 kWh/m²/day of solar energy in Wilkes Barre. The sunniest Septembers were 2005 and 2007 at 4.8 kWh/m²/day, and the cloudiest was 2018 at 3.
Average wind speed in Wilkes Barre during September is 0.1 m/s. The windiest Septembers were 2023, 2024 and 2025, among others at 0.1 m/s, while the calmest was 1981 at 0 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 16.7°C | 16.6°C | 17.4°C | 18.4°C | 18.1°C | +1.4°C |
| Avg High | 22.9°C | 22.6°C | 23.4°C | 24.4°C | 23.8°C | +0.9°C |
| Avg Low | 10.5°C | 10.7°C | 11.5°C | 12.4°C | 12.4°C | +1.9°C |
| Avg Rain | 99 mm | 114 mm | 122 mm | 121 mm | 115 mm | +17 mm |
September temperatures in Wilkes Barre have risen by about 1.5°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -0.1°C (2000) to a record high of 35.2°C (2002).
Rainfall in September is a relatively wet time of year, averaging 115 mm, with a wettest year of 336 mm.
One of the best times to visit Wilkes Barre
September is one of the best times to visit Wilkes Barre. Expect days averaging 23.4°C and nights around 11.4°C (mean 17.4°C) — warmer than Wilkes Barre's yearly average — with higher rainfall (115 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 | 25.9°C | 19.5°C | 13.1°C | 29.5°C | 8.0°C | 59 mm | 68% | 0.1 m/s | 4.4 |
| 2024 | 24.1°C | 18.3°C | 12.5°C | 28.9°C | 6.9°C | 46 mm | 75% | 0.1 m/s | 4.2 |
| 2023 | 23.2°C | 18.0°C | 12.7°C | 32.2°C | 6.9°C | 158 mm | 81% | 0.1 m/s | 4.1 |
| 2022 | 23.3°C | 17.7°C | 12.0°C | 29.8°C | 4.1°C | 108 mm | 76% | 0.1 m/s | 3.9 |
| 2021 | 22.7°C | 17.8°C | 12.9°C | 27.3°C | 6.8°C | 231 mm | 83% | 0.1 m/s | 3.9 |
| 2020 | 23.7°C | 17.5°C | 11.4°C | 29.5°C | 2.3°C | 91 mm | 72% | 0.1 m/s | 4.2 |
| 2019 | 25.3°C | 18.9°C | 12.5°C | 31.1°C | 6.0°C | 21 mm | 70% | 0.1 m/s | 4.1 |
| 2018 | 23.6°C | 19.0°C | 14.4°C | 30.3°C | 6.6°C | 199 mm | 87% | 0.1 m/s | 3 |
| 2017 | 24.3°C | 18.5°C | 12.7°C | 32.7°C | 5.6°C | 63 mm | 75% | 0.1 m/s | 4.3 |
| 2016 | 26.3°C | 19.7°C | 13.1°C | 32.9°C | 6.3°C | 80 mm | 65% | 0.1 m/s | 4.6 |
| 2015 | 26.1°C | 19.7°C | 13.3°C | 33.9°C | 8.3°C | 110 mm | 69% | 0.1 m/s | 4.5 |
| 2014 | 24.6°C | 18.2°C | 11.7°C | 31.4°C | 5.1°C | 33 mm | 69% | 0.1 m/s | 4.3 |
| 2013 | 23.3°C | 16.3°C | 9.4°C | 32.0°C | 3.0°C | 56 mm | 70% | 0.1 m/s | 4.6 |
| 2012 | 23.0°C | 17.2°C | 11.5°C | 31.0°C | 3.6°C | 155 mm | 76% | 0.1 m/s | 3.9 |
| 2011 🌧️ | 22.6°C | 18.1°C | 13.5°C | 28.4°C | 4.8°C | 336 mm | 88% | 0.1 m/s | 3.2 |
| 2010 | 25.0°C | 18.6°C | 12.3°C | 34.2°C | 6.3°C | 160 mm | 66% | 0.1 m/s | 4.1 |
| 2009 | 21.1°C | 15.9°C | 10.8°C | 25.9°C | 4.5°C | 75 mm | 80% | 0.1 m/s | 3.9 |
| 2008 | 24.1°C | 18.1°C | 12.1°C | 33.0°C | 5.8°C | 149 mm | 74% | 0.1 m/s | 4.2 |
| 2007 | 25.4°C | 18.7°C | 12.1°C | 30.9°C | 5.0°C | 43 mm | 70% | 0.1 m/s | 4.8 |
| 2006 | 20.3°C | 15.4°C | 10.6°C | 25.3°C | 3.5°C | 128 mm | 84% | 0.1 m/s | 3.3 |
| 2005 🔥 | 27.0°C | 20.0°C | 13.0°C | 33.1°C | 5.0°C | 32 mm | 62% | 0.1 m/s | 4.8 |
| 2004 | 23.1°C | 17.8°C | 12.5°C | 27.6°C | 5.7°C | 251 mm | 84% | 0.1 m/s | 4 |
| 2003 | 21.6°C | 16.8°C | 12.0°C | 25.8°C | 5.2°C | 209 mm | 85% | 0.1 m/s | 3.7 |
| 2002 | 25.6°C | 18.9°C | 12.2°C | 35.2°C | 6.3°C | 135 mm | 66% | 0.1 m/s | 4.2 |
| 2001 | 23.2°C | 16.4°C | 9.6°C | 29.3°C | 3.1°C | 115 mm | 68% | 0.1 m/s | 4.5 |
| 2000 | 22.6°C | 16.2°C | 9.7°C | 30.3°C | -0.1°C | 82 mm | 72% | 0.1 m/s | 3.9 |
| 1999 | 23.2°C | 17.4°C | 11.7°C | 32.5°C | 3.9°C | 243 mm | 77% | 0.1 m/s | 4 |
| 1998 | 24.9°C | 18.3°C | 11.6°C | 31.0°C | 3.5°C | 71 mm | 69% | 0.1 m/s | 4.3 |
| 1997 | 21.8°C | 15.9°C | 10.1°C | 27.9°C | 2.0°C | 85 mm | 73% | 0.1 m/s | 4.1 |
| 1996 | 22.3°C | 17.0°C | 11.7°C | 29.5°C | 4.0°C | 135 mm | 80% | 0.1 m/s | 3.6 |
| 1995 | 23.2°C | 16.6°C | 9.9°C | 30.8°C | 2.7°C | 75 mm | 64% | 0.1 m/s | 4.1 |
| 1994 | 21.3°C | 15.6°C | 10.0°C | 27.0°C | 5.6°C | 101 mm | 78% | 0.1 m/s | 3.8 |
| 1993 | 21.8°C | 16.5°C | 11.2°C | 30.4°C | 0.2°C | 165 mm | 79% | 0.1 m/s | 3.1 |
| 1992 | 22.2°C | 16.4°C | 10.6°C | 28.3°C | 2.2°C | 106 mm | 75% | 0.1 m/s | 3.8 |
| 1991 | 23.4°C | 16.8°C | 10.2°C | 32.4°C | 0.0°C | 85 mm | 66% | 0.1 m/s | 4.2 |
| 1990 | 22.0°C | 15.9°C | 9.8°C | 28.3°C | 1.2°C | 77 mm | 76% | 0.1 m/s | 4 |
| 1989 | 23.3°C | 17.5°C | 11.6°C | 32.9°C | 1.3°C | 127 mm | 75% | 0.1 m/s | 3.7 |
| 1988 | 21.9°C | 15.6°C | 9.2°C | 26.6°C | 3.2°C | 81 mm | 74% | 0.1 m/s | 4.3 |
| 1987 | 21.2°C | 16.2°C | 11.1°C | 25.8°C | 4.2°C | 212 mm | 84% | 0.1 m/s | 3.4 |
| 1986 | 22.9°C | 16.9°C | 10.9°C | 28.5°C | 2.5°C | 70 mm | 74% | 0.1 m/s | 3.5 |
| 1985 | 24.4°C | 17.9°C | 11.4°C | 31.5°C | 4.0°C | 164 mm | 69% | 0.1 m/s | 4.5 |
| 1984 ❄️ | 20.9°C | 14.6°C | 8.4°C | 26.7°C | 2.5°C | 30 mm | 75% | 0.1 m/s | 4.6 |
| 1983 | 25.3°C | 18.1°C | 10.9°C | 33.2°C | 3.1°C | 52 mm | 60% | 0.1 m/s | — |
| 1982 | 23.5°C | 17.1°C | 10.7°C | 29.8°C | 5.8°C | 64 mm | 69% | 0.1 m/s | — |
| 1981 | 22.3°C | 16.4°C | 10.6°C | 29.4°C | 3.2°C | 87 mm | 72% | 0 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 23.4°C with lows near 11.4°C (mean 17.4°C), based on 45 years of NASA POWER data.
September averages 115 mm of rainfall in Wilkes Barre, a relatively wet time of year. The wettest on record was 336 mm in 2011.
The hottest September reached 35.2°C in 2002. The coldest dipped to -0.1°C in 2000.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.5°C. Daytime highs moved from 23.3°C to 23.8°C and overnight lows from 10.4°C to 12.6°C over the same span.
September is one of the warmer months of the year in Wilkes Barre and a relatively wet time of year, so plan for around 23.4°C daytime highs and 11.4°C at night.
Not quite — September is the 9th coolest month in Wilkes Barre, averaging 17.4°C.
For September in Wilkes Barre, pack light layers you can adjust through the day, with typical highs of 23.4°C and lows of 11.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 74% — moderately humid.
Average wind speed in September is 0.1 m/s. The windiest September on record averaged 0.1 m/s (1982).
The wettest September on record was 2011 with 336 mm. On average, September sees 115 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 Wilkes Barre 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.
