September is one of the warmer months of the year in Hanover, with average highs near 25.4°C and lows around 13.5°C (mean 19.5°C). It is a relatively wet time of year, averaging 111 mm of rainfall and 70% relative humidity across the period.
September is one of the warmer months of the year in Hanover. Across 45 years of records, the warmest September in Hanover was 2019 — when the month averaged 22.4°C — while the coldest was 2000 at 17.3°C. Typical September days reach 25.4°C with nights near 13.5°C. The long-term trend is warming, about 0.5°C per decade.
September is a relatively wet time of year in Hanover, averaging 111 mm of rainfall. The wettest September on record was 2011 with 330 mm, while the driest was 2005 at 17 mm.
Relative humidity in Hanover during September averages 70%. The most humid Septembers were 2011 and 2018 at 88%, and the least humid was 1983 at 57%.
September receives about 4.3 kWh/m²/day of solar energy in Hanover. The sunniest September was 2007 at 5.2 kWh/m²/day, and the cloudiest was 2011 at 3.3.
Average wind speed in Hanover during September is 1.1 m/s. The windiest September was 1999 at 1.3 m/s, while the calmest were 2023, 2024 and 2025, among others at 1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 18.9°C | 18.7°C | 19.2°C | 20.3°C | 20.2°C | +1.3°C |
| Avg High | 25.2°C | 24.7°C | 25.2°C | 26.2°C | 26.1°C | +0.9°C |
| Avg Low | 12.7°C | 12.8°C | 13.4°C | 14.5°C | 14.3°C | +1.6°C |
| Avg Rain | 83 mm | 115 mm | 118 mm | 126 mm | 109 mm | +26 mm |
September temperatures in Hanover have risen by about 1.2°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 2.1°C (2000) to a record high of 36.9°C (2023).
Rainfall in September is a relatively wet time of year, averaging 111 mm, with a wettest year of 330 mm.
One of the best times to visit Hanover
September is one of the best times to visit Hanover. Expect days averaging 25.4°C and nights around 13.5°C (mean 19.5°C) — warmer than Hanover's yearly average — with higher rainfall (111 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 | 27.9°C | 21.5°C | 15.0°C | 32.6°C | 9.7°C | 54 mm | 62% | 1 m/s | 4.3 |
| 2024 | 25.9°C | 20.3°C | 14.7°C | 30.9°C | 8.6°C | 77 mm | 73% | 1 m/s | 4.1 |
| 2023 | 26.7°C | 20.7°C | 14.7°C | 36.9°C | 8.0°C | 121 mm | 70% | 1 m/s | 4.3 |
| 2022 | 25.6°C | 19.9°C | 14.2°C | 32.8°C | 7.0°C | 104 mm | 71% | 1.1 m/s | 4.6 |
| 2021 | 24.5°C | 19.3°C | 14.2°C | 29.1°C | 8.5°C | 235 mm | 82% | 1.1 m/s | 4.6 |
| 2020 | 25.7°C | 19.4°C | 13.2°C | 30.3°C | 3.7°C | 60 mm | 69% | 1.1 m/s | 4.2 |
| 2019 🔥 | 29.0°C | 22.4°C | 15.7°C | 35.8°C | 8.6°C | 22 mm | 63% | 1 m/s | 4.6 |
| 2018 | 24.9°C | 20.7°C | 16.6°C | 32.4°C | 9.2°C | 254 mm | 88% | 1 m/s | 3.4 |
| 2017 | 26.0°C | 20.0°C | 14.0°C | 33.4°C | 7.5°C | 54 mm | 70% | 1 m/s | 4.5 |
| 2016 | 28.0°C | 21.7°C | 15.5°C | 34.2°C | 8.7°C | 101 mm | 65% | 1.2 m/s | 4.3 |
| 2015 | 27.3°C | 21.1°C | 14.9°C | 35.0°C | 9.2°C | 107 mm | 68% | 1 m/s | 4.5 |
| 2014 | 26.1°C | 19.8°C | 13.5°C | 32.0°C | 6.7°C | 49 mm | 68% | 1 m/s | 4.5 |
| 2013 | 25.5°C | 18.8°C | 12.0°C | 34.6°C | 4.7°C | 41 mm | 64% | 1 m/s | 5 |
| 2012 | 24.5°C | 18.9°C | 13.3°C | 33.0°C | 5.5°C | 128 mm | 74% | 1.1 m/s | 4.6 |
| 2011 🌧️ | 23.4°C | 19.2°C | 14.9°C | 28.9°C | 5.1°C | 330 mm | 88% | 1 m/s | 3.3 |
| 2010 | 27.5°C | 20.9°C | 14.2°C | 36.0°C | 8.8°C | 171 mm | 62% | 1.2 m/s | 4.7 |
| 2009 | 22.9°C | 17.9°C | 13.0°C | 27.8°C | 7.9°C | 99 mm | 78% | 1.1 m/s | 4.1 |
| 2008 | 25.2°C | 19.6°C | 13.9°C | 34.0°C | 7.5°C | 170 mm | 74% | 1.1 m/s | 4.3 |
| 2007 | 27.4°C | 20.7°C | 14.0°C | 33.3°C | 6.0°C | 33 mm | 66% | 1 m/s | 5.2 |
| 2006 | 22.6°C | 17.6°C | 12.5°C | 27.9°C | 5.6°C | 139 mm | 80% | 1.1 m/s | 3.6 |
| 2005 | 28.7°C | 21.8°C | 14.9°C | 33.5°C | 6.1°C | 17 mm | 60% | 1 m/s | 5 |
| 2004 | 25.1°C | 19.7°C | 14.3°C | 29.0°C | 6.2°C | 206 mm | 80% | 1.1 m/s | 4 |
| 2003 | 23.6°C | 18.6°C | 13.6°C | 28.4°C | 5.1°C | 200 mm | 83% | 1.2 m/s | 4.1 |
| 2002 | 27.3°C | 20.8°C | 14.4°C | 34.7°C | 8.0°C | 107 mm | 64% | 1.2 m/s | 4.7 |
| 2001 | 25.3°C | 18.4°C | 11.6°C | 31.7°C | 5.0°C | 83 mm | 63% | 1.1 m/s | 4.7 |
| 2000 ❄️ | 23.4°C | 17.3°C | 11.3°C | 30.9°C | 2.1°C | 128 mm | 74% | 1.1 m/s | 4.4 |
| 1999 | 24.0°C | 18.5°C | 13.0°C | 31.7°C | 5.6°C | 256 mm | 76% | 1.3 m/s | 4.2 |
| 1998 | 28.4°C | 21.4°C | 14.4°C | 34.6°C | 5.1°C | 50 mm | 61% | 1.1 m/s | 4.8 |
| 1997 | 24.3°C | 18.2°C | 12.1°C | 32.2°C | 5.0°C | 85 mm | 68% | 1.2 m/s | 4.4 |
| 1996 | 23.2°C | 18.3°C | 13.3°C | 29.5°C | 7.6°C | 167 mm | 81% | 1.2 m/s | 3.9 |
| 1995 | 25.4°C | 18.9°C | 12.4°C | 32.8°C | 4.7°C | 72 mm | 61% | 1.1 m/s | 4.3 |
| 1994 | 23.5°C | 17.7°C | 11.8°C | 30.5°C | 5.8°C | 83 mm | 73% | 1.1 m/s | 4.6 |
| 1993 | 24.2°C | 18.8°C | 13.4°C | 32.6°C | 5.1°C | 165 mm | 74% | 1.1 m/s | 3.7 |
| 1992 | 24.1°C | 18.3°C | 12.5°C | 29.7°C | 3.5°C | 122 mm | 73% | 1.2 m/s | 4 |
| 1991 | 25.3°C | 18.9°C | 12.4°C | 34.6°C | 2.5°C | 95 mm | 65% | 1 m/s | 4.4 |
| 1990 | 24.6°C | 18.4°C | 12.2°C | 32.3°C | 3.1°C | 54 mm | 71% | 1.1 m/s | 4.3 |
| 1989 | 25.0°C | 19.3°C | 13.6°C | 33.9°C | 4.2°C | 84 mm | 73% | 1.1 m/s | 3.8 |
| 1988 | 24.2°C | 17.8°C | 11.4°C | 29.5°C | 6.4°C | 75 mm | 70% | 1.1 m/s | 4.4 |
| 1987 | 23.7°C | 18.5°C | 13.4°C | 27.6°C | 6.3°C | 191 mm | 80% | 1 m/s | 4.1 |
| 1986 | 25.6°C | 19.4°C | 13.2°C | 32.2°C | 4.2°C | 42 mm | 70% | 1.1 m/s | 4.1 |
| 1985 | 26.7°C | 20.0°C | 13.4°C | 34.6°C | 6.1°C | 114 mm | 63% | 1 m/s | 4.7 |
| 1984 | 24.1°C | 17.5°C | 10.8°C | 32.0°C | 4.3°C | 44 mm | 69% | 1.1 m/s | 4.7 |
| 1983 | 27.2°C | 20.1°C | 12.9°C | 36.0°C | 4.2°C | 45 mm | 57% | 1.1 m/s | — |
| 1982 | 25.7°C | 19.4°C | 13.1°C | 31.4°C | 7.9°C | 79 mm | 66% | 1 m/s | — |
| 1981 | 24.4°C | 18.3°C | 12.2°C | 32.1°C | 4.6°C | 69 mm | 68% | 1.2 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 25.4°C with lows near 13.5°C (mean 19.5°C), based on 45 years of NASA POWER data.
September averages 111 mm of rainfall in Hanover, a relatively wet time of year. The wettest on record was 330 mm in 2011.
The hottest September reached 36.9°C in 2023. The coldest dipped to 2.1°C in 2000.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.2°C. Daytime highs moved from 25.6°C to 26.1°C and overnight lows from 12.5°C to 14.6°C over the same span.
September is one of the warmer months of the year in Hanover and a relatively wet time of year, so plan for around 25.4°C daytime highs and 13.5°C at night.
Not quite — September is the 9th coolest month in Hanover, averaging 19.5°C.
For September in Hanover, pack light layers you can adjust through the day, with typical highs of 25.4°C and lows of 13.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 70% — moderately humid.
Average wind speed in September is 1.1 m/s. The windiest September on record averaged 1.3 m/s (1999).
The wettest September on record was 2011 with 330 mm. On average, September sees 111 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 Hanover 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.
