September is one of the warmer months of the year in Rochester, with average highs near 23.2°C and lows around 12°C (mean 17.6°C). It is a relatively wet time of year, averaging 88 mm of rainfall and 72% relative humidity across the period.
September is one of the warmer months of the year in Rochester. Across 45 years of records, the warmest September in Rochester was 2015 — when the month averaged 20.4°C — while the coldest was 1993 at 15.3°C. Typical September days reach 23.2°C with nights near 12°C. The long-term trend is warming, about 0.6°C per decade.
September is a relatively wet time of year in Rochester, averaging 88 mm of rainfall. The wettest September on record was 2006 with 156 mm, while the driest was 2025 at 32 mm.
Relative humidity in Rochester during September averages 72%. The most humid September was 2006 at 82%, and the least humid was 1991 at 63%.
September receives about 4 kWh/m²/day of solar energy in Rochester. The sunniest Septembers were 2005, 2023 and 2025 at 4.5 kWh/m²/day, and the cloudiest was 1990 at 3.2.
Average wind speed in Rochester during September is 0.5 m/s. The windiest September was 2010 at 0.6 m/s, while the calmest were 2002, 2003 and 2018, among others at 0.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 16.7°C | 16.5°C | 17.8°C | 18.5°C | 18.4°C | +1.7°C |
| Avg High | 22.3°C | 22.1°C | 23.5°C | 24.1°C | 24.0°C | +1.7°C |
| Avg Low | 11.2°C | 10.9°C | 12.1°C | 13.0°C | 12.9°C | +1.7°C |
| Avg Rain | 96 mm | 90 mm | 95 mm | 82 mm | 74 mm | -22 mm |
September temperatures in Rochester have risen by about 1.7°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 0°C (1991) to a record high of 34.2°C (2002).
Rainfall in September is a relatively wet time of year, averaging 88 mm, with a wettest year of 156 mm.
One of the best times to visit Rochester
September is one of the best times to visit Rochester. Expect days averaging 23.2°C and nights around 12°C (mean 17.6°C) — warmer than Rochester's yearly average — with higher rainfall (88 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 | 24.9°C | 18.8°C | 12.7°C | 28.4°C | 8.0°C | 32 mm | 69% | 0.5 m/s | 4.5 |
| 2024 | 25.2°C | 19.5°C | 13.9°C | 31.0°C | 8.9°C | 90 mm | 72% | 0.5 m/s | 4.3 |
| 2023 | 24.3°C | 18.6°C | 13.0°C | 34.2°C | 8.1°C | 49 mm | 72% | 0.5 m/s | 4.5 |
| 2022 | 22.4°C | 17.5°C | 12.6°C | 31.3°C | 4.3°C | 119 mm | 77% | 0.5 m/s | 3.7 |
| 2021 | 23.1°C | 18.0°C | 13.0°C | 28.7°C | 7.3°C | 98 mm | 75% | 0.5 m/s | 4 |
| 2020 | 24.0°C | 18.1°C | 12.2°C | 31.6°C | 3.9°C | 53 mm | 69% | 0.5 m/s | 4 |
| 2019 | 24.4°C | 18.6°C | 12.9°C | 30.8°C | 9.3°C | 71 mm | 75% | 0.5 m/s | 4.1 |
| 2018 | 24.7°C | 19.7°C | 14.7°C | 33.8°C | 6.8°C | 88 mm | 77% | 0.4 m/s | 4 |
| 2017 | 24.8°C | 19.1°C | 13.4°C | 33.1°C | 7.0°C | 56 mm | 71% | 0.5 m/s | 4.4 |
| 2016 | 25.8°C | 19.7°C | 13.6°C | 32.9°C | 7.0°C | 66 mm | 68% | 0.5 m/s | 4.4 |
| 2015 🔥 | 26.2°C | 20.4°C | 14.6°C | 33.6°C | 9.3°C | 127 mm | 71% | 0.5 m/s | 4.1 |
| 2014 | 23.5°C | 17.4°C | 11.4°C | 31.6°C | 4.4°C | 45 mm | 71% | 0.5 m/s | 4.3 |
| 2013 | 22.5°C | 16.6°C | 10.7°C | 32.8°C | 3.7°C | 55 mm | 70% | 0.5 m/s | 4.2 |
| 2012 | 23.1°C | 17.7°C | 12.3°C | 32.1°C | 7.2°C | 95 mm | 68% | 0.5 m/s | 4.1 |
| 2011 | 23.5°C | 18.6°C | 13.7°C | 33.0°C | 6.1°C | 104 mm | 77% | 0.5 m/s | 3.7 |
| 2010 | 22.9°C | 17.6°C | 12.3°C | 33.6°C | 6.2°C | 109 mm | 70% | 0.6 m/s | 3.5 |
| 2009 | 22.7°C | 17.1°C | 11.6°C | 29.6°C | 5.0°C | 56 mm | 73% | 0.5 m/s | 4.2 |
| 2008 | 23.5°C | 17.9°C | 12.3°C | 31.5°C | 5.3°C | 72 mm | 74% | 0.5 m/s | 3.9 |
| 2007 | 25.1°C | 18.9°C | 12.7°C | 34.1°C | 5.6°C | 76 mm | 67% | 0.5 m/s | 4.3 |
| 2006 🌧️ | 20.0°C | 15.5°C | 11.1°C | 26.7°C | 5.1°C | 156 mm | 82% | 0.5 m/s | 3.4 |
| 2005 | 24.8°C | 18.9°C | 13.0°C | 31.8°C | 5.8°C | 112 mm | 71% | 0.5 m/s | 4.5 |
| 2004 | 23.5°C | 18.4°C | 13.3°C | 29.6°C | 7.0°C | 128 mm | 78% | 0.5 m/s | 4.3 |
| 2003 | 22.8°C | 17.3°C | 11.7°C | 28.7°C | 5.6°C | 90 mm | 74% | 0.4 m/s | 4 |
| 2002 | 26.3°C | 19.9°C | 13.6°C | 34.2°C | 7.2°C | 85 mm | 63% | 0.4 m/s | 4.4 |
| 2001 | 23.0°C | 17.1°C | 11.3°C | 33.3°C | 5.2°C | 75 mm | 65% | 0.5 m/s | 4.2 |
| 2000 | 23.0°C | 16.8°C | 10.7°C | 33.2°C | 0.9°C | 95 mm | 69% | 0.5 m/s | 4 |
| 1999 | 24.8°C | 18.9°C | 13.0°C | 32.8°C | 6.9°C | 94 mm | 68% | 0.5 m/s | 4 |
| 1998 | 23.9°C | 18.1°C | 12.3°C | 30.6°C | 5.3°C | 71 mm | 69% | 0.5 m/s | 4.1 |
| 1997 | 21.5°C | 16.1°C | 10.7°C | 27.6°C | 3.0°C | 132 mm | 72% | 0.5 m/s | 3.6 |
| 1996 | 22.1°C | 17.0°C | 12.0°C | 30.4°C | 4.7°C | 129 mm | 77% | 0.4 m/s | 3.4 |
| 1995 | 21.6°C | 15.4°C | 9.1°C | 28.4°C | 2.1°C | 52 mm | 66% | 0.4 m/s | 4 |
| 1994 | 21.2°C | 16.0°C | 10.9°C | 28.6°C | 5.5°C | 73 mm | 74% | 0.5 m/s | 3.8 |
| 1993 ❄️ | 20.6°C | 15.3°C | 9.9°C | 30.4°C | 0.3°C | 102 mm | 73% | 0.5 m/s | 3.3 |
| 1992 | 21.6°C | 16.0°C | 10.4°C | 28.7°C | 1.5°C | 98 mm | 76% | 0.5 m/s | 3.7 |
| 1991 | 22.3°C | 16.1°C | 10.0°C | 32.7°C | 0.0°C | 62 mm | 63% | 0.5 m/s | 3.8 |
| 1990 | 21.7°C | 16.4°C | 11.0°C | 30.3°C | 3.9°C | 84 mm | 72% | 0.5 m/s | 3.2 |
| 1989 | 22.3°C | 16.8°C | 11.3°C | 31.1°C | 1.4°C | 95 mm | 73% | 0.4 m/s | 3.7 |
| 1988 | 22.8°C | 16.5°C | 10.2°C | 29.7°C | 3.7°C | 53 mm | 66% | 0.5 m/s | 4.1 |
| 1987 | 21.6°C | 16.5°C | 11.5°C | 28.2°C | 6.1°C | 125 mm | 79% | 0.4 m/s | 3.5 |
| 1986 | 22.2°C | 16.7°C | 11.3°C | 27.6°C | 5.2°C | 125 mm | 74% | 0.5 m/s | 3.4 |
| 1985 | 23.9°C | 18.0°C | 12.1°C | 31.3°C | 5.9°C | 90 mm | 70% | 0.5 m/s | 4 |
| 1984 | 20.8°C | 15.4°C | 10.1°C | 26.9°C | 3.0°C | 106 mm | 74% | 0.5 m/s | 4 |
| 1983 | 24.1°C | 18.1°C | 12.1°C | 32.0°C | 5.6°C | 54 mm | 64% | 0.5 m/s | — |
| 1982 | 23.0°C | 17.0°C | 10.9°C | 31.8°C | 5.1°C | 88 mm | 71% | 0.5 m/s | — |
| 1981 | 20.3°C | 15.7°C | 11.2°C | 29.6°C | 2.1°C | 126 mm | 78% | 0.5 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 23.2°C with lows near 12°C (mean 17.6°C), based on 45 years of NASA POWER data.
September averages 88 mm of rainfall in Rochester, a relatively wet time of year. The wettest on record was 156 mm in 2006.
The hottest September reached 34.2°C in 2002. The coldest dipped to 0°C in 1991.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.7°C. Daytime highs moved from 22.4°C to 24°C and overnight lows from 11.3°C to 13°C over the same span.
September is one of the warmer months of the year in Rochester and a relatively wet time of year, so plan for around 23.2°C daytime highs and 12°C at night.
Not quite — September is the 9th coolest month in Rochester, averaging 17.6°C.
For September in Rochester, pack light layers you can adjust through the day, with typical highs of 23.2°C and lows of 12°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 72% — moderately humid.
Average wind speed in September is 0.5 m/s. The windiest September on record averaged 0.6 m/s (2010).
The wettest September on record was 2006 with 156 mm. On average, September sees 88 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 Rochester 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.
