September is one of the warmer months of the year in Hanover, with average highs near 20.3°C and lows around 7.9°C (mean 14.1°C). It is about average for rainfall, averaging 53 mm of rainfall and 69% 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 2024 — when the month averaged 19.1°C — while the coldest was 1985 at 10.2°C. Typical September days reach 20.3°C with nights near 7.9°C. The long-term trend is warming, about 0.8°C per decade.
September is about average for rainfall in Hanover, averaging 53 mm of rainfall. The wettest September on record was 2019 with 156 mm, while the driest was 1998 at 14 mm.
Relative humidity in Hanover during September averages 69%. The most humid September was 2004 at 78%, and the least humid was 2012 at 56%.
September receives about 3.7 kWh/m²/day of solar energy in Hanover. The sunniest Septembers were 2009 and 2011 at 4.2 kWh/m²/day, and the cloudiest were 1992, 1999 and 2019, among others at 3.2.
Average wind speed in Hanover during September is 2.9 m/s. The windiest Septembers were 1985, 1991 and 2017 at 3.3 m/s, while the calmest was 1987 at 2.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.8°C | 13.6°C | 14.3°C | 14.2°C | 16.6°C | +3.8°C |
| Avg High | 18.9°C | 19.9°C | 20.5°C | 20.4°C | 22.9°C | +4°C |
| Avg Low | 6.7°C | 7.3°C | 8.2°C | 7.9°C | 10.3°C | +3.6°C |
| Avg Rain | 49 mm | 52 mm | 52 mm | 69 mm | 34 mm | -15 mm |
September temperatures in Hanover have risen by about 5.3°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -4.7°C (2018) to a record high of 36.2°C (2023).
Rainfall in September is about average for rainfall, averaging 53 mm, with a wettest year of 156 mm.
One of the best times to visit Hanover
September is one of the best times to visit Hanover. Expect days averaging 20.3°C and nights around 7.9°C (mean 14.1°C) — warmer than Hanover's yearly average — with moderate rainfall (53 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 | 23.8°C | 17.7°C | 11.7°C | 30.1°C | 3.0°C | 39 mm | 69% | 2.8 m/s | 3.4 |
| 2024 🔥 | 25.4°C | 19.1°C | 12.8°C | 31.6°C | 5.8°C | 41 mm | 65% | 3.1 m/s | 3.8 |
| 2023 | 23.9°C | 17.8°C | 11.7°C | 36.2°C | 5.3°C | 42 mm | 67% | 2.7 m/s | 3.6 |
| 2022 | 21.4°C | 15.2°C | 8.9°C | 31.9°C | 1.1°C | 32 mm | 67% | 2.9 m/s | 4 |
| 2021 | 23.5°C | 17.0°C | 10.5°C | 30.2°C | 6.2°C | 22 mm | 64% | 3.1 m/s | 3.9 |
| 2020 | 19.2°C | 12.7°C | 6.2°C | 28.5°C | -0.1°C | 25 mm | 67% | 3.2 m/s | 3.7 |
| 2019 🌧️ | 19.5°C | 14.0°C | 8.5°C | 29.1°C | -0.1°C | 156 mm | 78% | 2.8 m/s | 3.2 |
| 2018 | 18.5°C | 12.4°C | 6.4°C | 30.8°C | -4.7°C | 42 mm | 68% | 3 m/s | 3.4 |
| 2017 | 20.9°C | 14.9°C | 8.9°C | 33.5°C | 3.9°C | 90 mm | 70% | 3.3 m/s | 3.6 |
| 2016 | 20.8°C | 14.8°C | 8.7°C | 29.9°C | 2.5°C | 74 mm | 73% | 3.1 m/s | 3.5 |
| 2015 | 23.1°C | 16.4°C | 9.6°C | 32.8°C | 0.1°C | 48 mm | 68% | 3.1 m/s | 4 |
| 2014 | 20.0°C | 13.6°C | 7.1°C | 27.8°C | 0.8°C | 48 mm | 75% | 3 m/s | 3.7 |
| 2013 | 22.6°C | 16.1°C | 9.6°C | 31.2°C | 2.1°C | 42 mm | 68% | 2.9 m/s | 3.8 |
| 2012 | 20.5°C | 13.7°C | 7.0°C | 30.1°C | -1.9°C | 25 mm | 56% | 3.1 m/s | 3.7 |
| 2011 | 20.7°C | 14.0°C | 7.4°C | 30.4°C | -0.4°C | 58 mm | 68% | 3 m/s | 4.2 |
| 2010 | 17.0°C | 11.6°C | 6.2°C | 23.8°C | -0.7°C | 110 mm | 76% | 3.2 m/s | 3.6 |
| 2009 | 24.2°C | 17.9°C | 11.6°C | 29.5°C | -0.3°C | 48 mm | 73% | 2.8 m/s | 4.2 |
| 2008 | 19.5°C | 13.7°C | 8.0°C | 28.9°C | 2.8°C | 81 mm | 74% | 2.8 m/s | 3.6 |
| 2007 | 20.1°C | 13.7°C | 7.4°C | 30.9°C | -0.3°C | 30 mm | 70% | 3.2 m/s | 3.4 |
| 2006 | 20.5°C | 14.0°C | 7.4°C | 30.7°C | -0.3°C | 60 mm | 67% | 2.7 m/s | 3.9 |
| 2005 | 20.9°C | 14.7°C | 8.6°C | 28.3°C | 2.4°C | 31 mm | 72% | 2.7 m/s | 4.1 |
| 2004 | 20.5°C | 14.8°C | 9.1°C | 31.0°C | 2.6°C | 77 mm | 78% | 2.7 m/s | 3.4 |
| 2003 | 18.7°C | 13.2°C | 7.7°C | 31.6°C | -2.8°C | 61 mm | 72% | 3.2 m/s | 3.4 |
| 2002 | 21.3°C | 14.9°C | 8.5°C | 31.0°C | -2.6°C | 61 mm | 68% | 2.9 m/s | 3.8 |
| 2001 | 20.9°C | 14.2°C | 7.5°C | 33.1°C | -1.4°C | 21 mm | 67% | 2.5 m/s | 4 |
| 2000 | 18.3°C | 12.1°C | 6.0°C | 28.1°C | -1.7°C | 51 mm | 71% | 3.1 m/s | 3.5 |
| 1999 | 17.3°C | 11.8°C | 6.3°C | 26.0°C | -1.3°C | 51 mm | 73% | 2.9 m/s | 3.2 |
| 1998 | 22.4°C | 15.7°C | 9.0°C | 32.8°C | 2.5°C | 14 mm | 65% | 2.8 m/s | 4.1 |
| 1997 | 21.9°C | 15.5°C | 9.1°C | 27.9°C | 1.7°C | 34 mm | 65% | 3.2 m/s | 3.9 |
| 1996 | 20.2°C | 14.1°C | 7.9°C | 31.9°C | -1.1°C | 60 mm | 68% | 2.5 m/s | 3.6 |
| 1995 | 19.8°C | 13.3°C | 6.8°C | 32.5°C | -1.6°C | 60 mm | 65% | 2.6 m/s | 4.1 |
| 1994 | 22.2°C | 15.8°C | 9.3°C | 30.3°C | 2.3°C | 65 mm | 68% | 2.7 m/s | 3.9 |
| 1993 | 16.9°C | 10.8°C | 4.6°C | 24.5°C | -0.7°C | 18 mm | 72% | 3.1 m/s | 3.4 |
| 1992 | 18.5°C | 12.0°C | 5.6°C | 26.1°C | -3.4°C | 48 mm | 69% | 3.2 m/s | 3.2 |
| 1991 | 18.5°C | 12.5°C | 6.6°C | 30.3°C | -1.7°C | 137 mm | 68% | 3.3 m/s | 3.7 |
| 1990 | 21.7°C | 14.9°C | 8.1°C | 31.0°C | -0.2°C | 29 mm | 62% | 3.1 m/s | 3.9 |
| 1989 | 21.1°C | 14.2°C | 7.3°C | 30.4°C | -2.0°C | 21 mm | 62% | 3.1 m/s | 4.1 |
| 1988 | 19.7°C | 13.5°C | 7.3°C | 30.0°C | 1.8°C | 50 mm | 63% | 3.2 m/s | 3.5 |
| 1987 | 21.0°C | 14.8°C | 8.6°C | 31.0°C | 2.7°C | 32 mm | 66% | 2.3 m/s | 3.6 |
| 1986 | 18.0°C | 12.3°C | 6.7°C | 24.1°C | -0.1°C | 57 mm | 72% | 2.5 m/s | 3.2 |
| 1985 ❄️ | 15.6°C | 10.2°C | 4.8°C | 24.2°C | -3.8°C | 52 mm | 74% | 3.3 m/s | 3.2 |
| 1984 | 16.9°C | 10.9°C | 4.8°C | 26.2°C | -4.4°C | 37 mm | 65% | 2.8 m/s | 3.5 |
| 1983 | 18.6°C | 12.9°C | 7.3°C | 32.5°C | -1.1°C | 71 mm | 70% | 3.1 m/s | — |
| 1982 | 19.7°C | 13.3°C | 6.9°C | 32.7°C | 0.3°C | 45 mm | 67% | 3.1 m/s | — |
| 1981 | 19.3°C | 13.0°C | 6.8°C | 29.0°C | -0.6°C | 78 mm | 68% | 3 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 20.3°C with lows near 7.9°C (mean 14.1°C), based on 45 years of NASA POWER data.
September averages 53 mm of rainfall in Hanover, about average for rainfall. The wettest on record was 156 mm in 2019.
The hottest September reached 36.2°C in 2023. The coldest dipped to -4.7°C in 2018.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 5.3°C. Daytime highs moved from 18°C to 23.6°C and overnight lows from 6.1°C to 11.1°C over the same span.
September is one of the warmer months of the year in Hanover and about average for rainfall, so plan for around 20.3°C daytime highs and 7.9°C at night.
Not quite — September is the 9th coolest month in Hanover, averaging 14.1°C.
For September in Hanover, pack warm layers and a jacket for chilly mornings, with typical highs of 20.3°C and lows of 7.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 69% — moderately humid.
Average wind speed in September is 2.9 m/s. The windiest September on record averaged 3.3 m/s (1985).
The wettest September on record was 2019 with 156 mm. On average, September sees 53 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.
