September Weather in Bad Honnef, Germany

Last updated: February 26, 2025

In September, Bad Honnef experiences a dynamic shift in weather, with maximum temperatures reaching up to 33°C (92°F), offering warmth during the day. The average temperature sits comfortably at 15°C (60°F), while cooler nights drop to a minimum of 2°C (36°F). This month typically sees 61 mm (2.4 in) of precipitation spread over 10 days, along with a high humidity level of 81%, creating a humid atmosphere. This blend of warmth and moisture not only defines the charm of Bad Honnef but also invites outdoor enthusiasts to explore the area’s natural beauty amidst changing conditions.

September Temperature in Bad Honnef

In September, Bad Honnef experiences a delightful transition into autumn, where the temperatures start to cool after the summer heat. With minimums around 2°C (36°F) and average highs reaching up to 33°C (92°F), this month showcases a broad range of temperatures, highlighting its variability. The average temperature settles at a comfortable 15°C (60°F), making outdoor activities quite enjoyable. Although the summer retains some of its warmth at the beginning of the month, the increasing coolness hints at the changing season, offering a refreshing contrast to the sweltering summer months that just preceded it. As the days grow shorter, September invites visitors to embrace the beauty of nature’s transition, immersing themselves in the stunning landscapes of this charming German town.

September Weather in Bad Honnef: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Bad Honnef, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec374044505766676760534440
Data source: Temperature data for Bad Honnef generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Bad Honnef

In September, Bad Honnef experiences a moderate precipitation level, receiving approximately 61 mm (2.4 in) of rain over 10 days. This marks a notable decrease from the summer months, where July and August saw higher rainfall totals of 91 mm and 82 mm respectively. The shift towards milder precipitation paves the way for the onset of autumn, as the region transitions into a season characterized by increased rainfall, peaking again in December with 118 mm. Overall, September serves as a bridge between the wetter summer months and the impending autumn rains, reflecting a typical trend of diminishing moisture as the year progresses.

September Precipitation Trends in Bad Honnef

The chart displays monthly precipitation patterns in Bad Honnef, with values for each month alongside September's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec8379853973679182618059118
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Bad Honnef

As summer transitions into autumn, September in Bad Honnef, Germany experiences a notable increase in humidity, rising to 81%. This shift marks a temporary respite from the steadily declining moisture levels observed during the warmer months, where July and August registered their lowest points at 72% and 71%, respectively. However, September's humidity reflects both a lingering warmth from the summer and the approaching cooler fall weather, bridging the gap between the dry tendencies of mid-year and the wetter autumn months ahead. Following this month, the humidity rises again in October to 88%, hinting at the return of the dampness characteristic of Bad Honnef's winter season. This pattern showcases the region's unique climate rhythm, where the interplay between humidity and seasonal changes creates a vibrant tapestry of atmospheric conditions.

September Average Humidity in Bad Honnef

This chart illustrates the average monthly humidity levels in Bad Honnef, with September's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec91%90%87%84%77%74%72%71%81%88%91%92%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Bad Honnef

As summer transitions to fall, September's UV Index in Bad Honnef, Germany, reflects a noticeable shift. With a UV Index of 5, categorized as moderate, residents and visitors have about 30 minutes of burn time before sun exposure becomes a concern. This marks a decrease from the peak summer months, where UV levels soared to 8, necessitating heightened sun safety measures. While September still encourages outdoor activities, it's a reminder to stay vigilant about skin protection, especially as the days grow shorter. Embrace the beautiful fall weather, but don't forget to check the UV Index for safe enjoyment. For more detailed insights, visit Bad Honnef UV Index.

Maximum UV Index Levels in Bad Honnef for September

The chart shows the monthly maximum UV Index (UVI) for Bad Honnef in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec124578875421
Data source: Bad Honnef September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Bad Honnef

In September, Bad Honnef basks in a generous 314 hours of sunlight, marking a beautiful transition from the sun-soaked summer months. As the summer peaks in July with an impressive 409 hours, this charming town sees a gradual decline in sunny days leading into autumn. September retains a significant amount of sunshine, allowing locals and visitors alike to enjoy the soft, warm days before the year’s light dwindles. Following this month, a noticeable drop occurs in October, with just 230 hours, hinting at the approaching winter. This seasonal rhythm highlights how Bad Honnef makes the most of its late summer sunshine, setting the stage for cozy, crisp fall days ahead.

Monthly Sunshine Duration in Bad Honnef: September Highlighted

The September sunshine duration represents the total number of hours Bad Honnef experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec106h199h263h341h389h392h409h380h314h230h173h117h
Data source: Bad Honnef September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Bad Honnef During September

In September, Bad Honnef typically enjoys a 38% chance of sunny weather, marking a slight improvement from the preceding summer months. This percentage reflects the transition from the warm haze of summer into the more unpredictable autumn skies. Compared to the early months of the year, where sunshine is a rarity—peaking at just 10% in January—September's chances signal a lovely, lingering warmth. This trend highlights a gradual climb from April's 39% through the summer, suggesting that while fall is arriving, there's still ample opportunity to bask in the sun's rays before the colder months settle in. So, if you find yourself in Bad Honnef this September, keep your fingers crossed for a few bright days ahead!

Percentage of Sunny Days in September in Bad Honnef

The chart illustrates the percentage of sunny days in Bad Honnef throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Bad Honnef experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec10%32%42%40%30%30%31%32%38%28%22%13%
Data source: Bad Honnef September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Bad Honnef in September

As summer fades in Bad Honnef, Germany, September brings a moderate 12 hours of daylight, marking yet another transition in the seasonal rhythm. Following the peak of 16 hours in June, daylight begins its gradual retreat, a trend that continues into the cooler months. Compared to the previous months—where May and July flaunt 15 hours—September offers a noticeable drop, signaling the onset of autumn. This gradual decrease from August's 14 hours highlights the shift towards the shorter days of October and November, which linger around 10 hours and 8 hours, respectively. As nature prepares for the changing seasons, the diminishing sunlight in September invites a reflective pause before the darker months follow.

Average Daylight Hours in Bad Honnef for September

The chart illustrates the variation in daylight duration in Bad Honnef throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 31m10h 2m11h 55m13h 50m15h 30m16h 23m15h 55m14h 25m12h 34m10h 39m8h 56m8h 2m
Data source: Bad Honnef daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Bad Honnef

As September arrives in Bad Honnef, Germany, the decline in average wind speed becomes evident, with gentle breezes reaching only 2.2 m/s (5 mph). This marks a noticeable shift from the more robust winds experienced earlier in the year, particularly in January and October, which showcase an average of 3.5 m/s (8 mph). The months prior to September also see comparatively higher wind speeds, with May registering 3.4 m/s and June dropping to a milder 2.4 m/s. The trend indicates a gradual wind reduction as summer fades, leading into the crispness of autumn. In contrast to this late-summer lull, the winds pick up again towards the end of the year, suggesting a cyclical rhythm that characterizes Bad Honnef's seasonal weather patterns.

Average September Wind Speed in Bad Honnef

The chart displays monthly wind speed patterns in Bad Honnef, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.53.73.32.93.42.42.52.82.2 m/s3.52.63.3
Data source: Bad Honnef September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Bad Honnef Compares to Other Months

The weather in Bad Honnef changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Bad Honnef and find detailed weather information for every month.

September and January present stark contrasts in weather conditions. September enjoys warmer temperatures, with averages around 15°C (60°F) and highs peaking at 33°C (92°F), making it a much more pleasant month for outdoor activities. In contrast, January experiences a significant chill, with average temperatures dropping to 3°C (38°F) and lows reaching -8°C (17°F). Precipitation is slightly more frequent in January, occurring on 14 days compared to 10 days in September, with a total of 83 mm (3.3 in) of rainfall. Additionally, humidity levels are higher in January at 91%, compared to 81% in September, contributing to a colder, damp atmosphere. For a deeper understanding of January's weather in Bad Honnef, you can visit Bad Honnef weather in January.

September and February present quite contrasting weather patterns. In September, temperatures can range from a mild 15°C (60°F) on average to a hot maximum of 33°C (92°F), with a notable drop to a minimum of 2°C (36°F). The month experiences a fair amount of rain, receiving about 61 mm (2.4 in) over roughly 10 days, accompanied by relatively high humidity at 81%. In stark contrast, February features much chillier conditions, with average temperatures around 4°C (40°F), peaking at 20°C (68°F) and plummeting to a chilly -11°C (13°F) at night. This month sees slightly more precipitation, totaling 79 mm (3.1 in) across 12 days, and even higher humidity at 90%. For a more detailed look at February weather, you can refer to Bad Honnef weather in February.

September and March present contrasting weather experiences. In September, temperatures range significantly, with a minimum of 2°C (36°F) and a comfortable average of 15°C (60°F), peaking at a warm 33°C (92°F). This month typically sees about 61 mm (2.4 in) of rainfall over 10 days, with humidity levels around 81%. In comparison, March is notably cooler, with temperatures ranging from a chilly -10°C (14°F) to a maximum of 22°C (73°F) and an average of 7°C (44°F). Additionally, March experiences higher precipitation, totaling 85 mm (3.3 in) over 16 days, and a slightly increased humidity of 87%. For a detailed look at the conditions during this month, visit Bad Honnef weather in March.

When comparing the weather in September and April, notable differences emerge in temperature and precipitation patterns. September boasts a wider temperature range, with minimums around 2°C (36°F) and maximums soaring up to 33°C (92°F), while April experiences cooler temperatures, ranging from a minimum of -3°C (26°F) to a maximum of 27°C (80°F). Additionally, September sees more precipitation, averaging 61 mm (2.4 in) across 10 days, compared to April's 39 mm (1.5 in) over 9 days. Both months exhibit high humidity levels, with September at 81% and April slightly higher at 84%. For a closer look at April's weather specifics, you can check out Bad Honnef weather in April.

When comparing the weather in September and May, both months experience similar maximum temperatures, reaching around 33°C (92°F) in September and 33°C (91°F) in May. However, September tends to be slightly warmer on average, with a minimum temperature of 2°C (36°F) compared to May's 0°C (33°F). Precipitation is also a bit more prevalent in May, with 73 mm (2.9 in) over 13 days, compared to September's 61 mm (2.4 in) over 10 days. Additionally, September has a higher humidity level at 81% compared to May's 77%. For a detailed look at the weather during this time, you can check out Bad Honnef weather in May.

In comparing the weather of September and June, we see notable differences in temperature and humidity. September features a temperature range that starts at a cooler minimum of 2°C (36°F) and peaks at a warm 33°C (92°F), with an average of 15°C (60°F). In contrast, June has a higher minimum temperature of 8°C (46°F) and averages 19°C (66°F), reaching a maximum of 35°C (95°F). Both months experience similar levels of precipitation, with September receiving 61 mm (2.4 in) across 10 days, while June has slightly more at 67 mm (2.6 in) over 11 days. Additionally, September’s humidity is higher at 81%, compared to June's 74%. For more detailed insights, you can check Bad Honnef weather in June.

When comparing the weather in September to that of July, noticeable differences emerge. September typically sees a wider range in temperatures, with a minimum of 2°C (36°F) and a maximum reaching up to 33°C (92°F), averaging around 15°C (60°F). In contrast, July has warmer conditions, with a minimum of 8°C (47°F) and a maximum soaring to 40°C (104°F), averaging 19°C (67°F). Precipitation in September is slightly lower at 61 mm (2.4 in) over about 10 days, while July experiences more rainfall at 91 mm (3.6 in) across 11 days. Additionally, September tends to be more humid, averaging 81% compared to July's 72%. For more detailed insights, check out Bad Honnef weather in July.

In comparing the weather between August and September, we can observe notable differences in temperature, precipitation, and humidity. August experiences a higher average temperature of 19°C (67°F), with maximums reaching up to 36°C (97°F), while September shows a decrease in average temperature to 15°C (60°F) and a maximum of 33°C (92°F). Precipitation is also more prevalent in August, with 82 mm (3.2 in) recorded over 15 days, compared to September, which has 61 mm (2.4 in) over 10 days. Interestingly, September has a higher humidity level at 81%, compared to August's 71%. For more details on August weather, you can visit Bad Honnef weather in August.

In comparing the weather of September and October, notable differences emerge. September typically boasts a wider temperature range, with minimums around 2°C (36°F) and maximums reaching up to 33°C (92°F), resulting in an average of 15°C (60°F). This month experiences an average of 61 mm (2.4 in) of precipitation over about 10 days, with a relative humidity of 81%. In contrast, October sees cooler temperatures, with minimums at 1°C (33°F) and maximums capped at 26°C (79°F), averaging 12°C (53°F). Additionally, October brings more precipitation, totaling 80 mm (3.2 in) across approximately 14 days, accompanied by increased humidity at 88%. For more detailed forecasts, check out Bad Honnef weather in October.

When comparing the weather in September and November, notable differences emerge. In September, temperatures range from a minimum of 2°C (36°F) to a maximum of 33°C (92°F), with an average of 15°C (60°F). This month also experiences 61 mm (2.4 in) of precipitation over about 10 days and has a humidity level of 81%. In contrast, November presents a cooler climate with temperatures dropping to a minimum of -4°C (25°F) and peaking at 20°C (68°F), averaging 7°C (44°F). The precipitation level is slightly lower at 59 mm (2.3 in), but it occurs over more days—13 in total—and humidity increases to 91%. For more specific insights on the weather in November, you can check Bad Honnef weather in November.

September features a much warmer climate, with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 33°C (92°F), and an average of 15°C (60°F). The month experiences moderate precipitation of 61 mm (2.4 in) across about 10 days, while humidity levels sit at a relatively comfortable 81%. In contrast, December brings a chillier atmosphere, with temperatures dropping to a minimum of -5°C (23°F) and peaking at 15°C (59°F), leading to an average temperature of 5°C (41°F). Rainfall increases to 118 mm (4.7 in) over about 20 days, and humidity climbs to 92%, creating a damp and colder environment. For more details on December weather, you can visit Bad Honnef weather in December.

Compare Bad Honnef's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Bad Honnef

As September unfolds in Bad Honnef, the weather presents a delightful blend of summer's warmth and the crisp beginnings of autumn. With maximum temperatures reaching up to 33°C (92°F), the month still holds onto the heat, albeit gradually giving way to cooler averages of 15°C (60°F) and occasional dips to as low as 2°C (36°F). Rainfall is moderate, with 61 mm (2.4 in) spread across about 10 days, and humidity remains high at 81%, creating a unique atmospheric experience. Compared to the hot summer months, September offers a refreshing transition, making it an ideal time for outdoor activities while enjoying the vibrant changes in nature. For a deeper look into what to expect, explore more about the area at Bad Honnef Climate.