Last updated: August 27, 2025
In September, Riehen, Switzerland experiences a captivating mix of weather patterns, with maximum temperatures reaching 30°C (86°F) and an average of 16°C (61°F), allowing for delightful early autumn days. However, temperatures can dip as low as 2°C (36°F), reminding residents and visitors alike of the approaching chill. The month witnesses a total precipitation of 69 mm (2.7 in) over 12 days, creating a lush backdrop as humidity hovers at a notable 83%. This blend of warmth and moisture contributes to the region's stunning natural beauty, making September a unique time to explore Riehen's landscapes.
In September, Riehen, Switzerland transitions gracefully from summer to autumn, offering a delightful temperate climate. With average temperatures hovering around 16°C (61°F), the month strikes a perfect balance between the warm days of summer and the cooler evenings ahead. Daily highs can reach up to 30°C (86°F), ensuring plenty of sunshine for outdoor activities, while nighttime lows dipping to 2°C (36°F) remind residents of the coming change in seasons. This unique blend of warmth and crisp, cool air sets the stage for stunning fall foliage, making September an enchanting time to explore Riehen's natural beauty.
In September, Riehen, Switzerland, experiences a moderate precipitation amount of 69 mm (2.7 in) spread over 12 days, marking a gentle transition into autumn. While this month witnesses a slight decline compared to the wetter summer months, it remains significant among the year’s precipitation patterns. Notably, September's rainfall is less than the peaks seen in May (126 mm) and July (122 mm), yet it aligns with the consistent precipitation observed earlier in the year. This gradual tapering off hints at nature's preparations for the drier fall months ahead, creating a delicate balance in the region's hydrological cycle.
In Riehen, Switzerland, September brings a hint of transition as humidity levels settle at 83%. This level is a slight increase from the previous months, maintaining a comfortable balance that characterizes the late summer and early autumn months. Following a trend of diminishing humidity from the peak in January at 92%, the region enjoys a gradual decline throughout the spring, reaching its lowest in May with 80%. However, as summer fades into autumn, humidity levels begin to rise again, a precursor to the wetter months ahead. With October jumping back up to 90%, Riehen seems to brace for the cooler, moister days of fall, painting a vivid picture of a landscape that thrives in the rhythm of the changing seasons.
As September unfolds in Riehen, Switzerland, residents experience a high UV Index of 6, marking a decline from the peak summer months. The burn time increases to 25 minutes, providing a bit more leeway for outdoor activities compared to the previous months, where a swift 15-minute exposure was common during the intense July and August sun. As autumn approaches, the UV Index trends downwards, transitioning from the very high exposure categories observed earlier in the summer. This seasonal shift encourages individuals to enjoy the inviting early autumn days while remaining mindful of sun safety. To keep informed about UV levels and protect your skin, visit Riehen UV Index.
UV Risk Categories
As the summer fades away, September in Riehen, Switzerland, continues to bask in a generous 323 hours of sunshine. This radiant month bridges the vibrant energy of summer, with its peak in July at an impressive 413 hours, and the gentle retreat into the cooler autumn months, where October sees a decline to 265 hours. Interestingly, September's sunshine is notably higher than both its preceding and following months, suggesting a lingering warmth and bright days that invite outdoor activities. The transition into fall is marked by a noticeable decrease in daylight hours, but September’s rich sunlight offers a vibrant farewell to summer, setting the stage for the tranquil beauty of autumn to unfold.
As September arrives in Riehen, Switzerland, the likelihood of enjoying sunny weather shows a promising trend with a 43% chance of sunshine. This marks a slight improvement from the summer months, where the chances hovered around 38% to 39%. Notably, September's sunny potential stands out as one of the more favorable periods of the year, particularly as it follows the relatively brighter spring months of April and May. While the chances of sun may dip again in the upcoming fall months, September offers a delightful opportunity to bask in the fading warmth and enjoy the changing hues of the landscape.
As summer transitions into autumn, September in Riehen, Switzerland offers a delightful 12 hours of daylight, marking a gradual decline from the peak of 15 hours enjoyed during the summer months. This decrease reflects the natural progression of the seasons, as the long, sunlit days of May through August slowly give way to the shorter, cozier days of fall. The cooler air and shifting light also herald the change in scenery, with vibrant autumn colors illuminating the landscape. Following September, the daylight dwindles to 10 hours in October, setting the stage for the quiet, reflective months ahead. The rhythmic ebb and flow of sunlight throughout the year create a captivating experience for residents and visitors alike.
In September, Riehen, Switzerland, experiences a gentle sigh as the average wind speed dips to 1.6 m/s (4 mph), marking one of the year's calmest months. This trend of diminishing winds can be traced back through the summer, where breezes lingered around 1.9 m/s (4 mph) in both July and August. In stark contrast, the higher velocities of earlier months, such as May's pleasant 2.7 m/s (6 mph), hint at a transition from the lively gusts of spring to the tranquil breezes that herald autumn. As the year progresses, winds gradually return to a more brisk pace, with October anticipating a slight uptick to 1.9 m/s (4 mph). Thus, September stands out not only for its serene beauty but also as a bridge between the vibrant energy of summer and the cool embrace of fall.
Weather in Riehen varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Riehen, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present strikingly different weather patterns. September typically enjoys a milder climate, with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 30°C (86°F), and an average temperature of 16°C (61°F). The month sees about 69 mm (2.7 in) of precipitation over approximately 12 days, accompanied by a humidity level of 83%. In contrast, January is much colder, with temperatures dropping to a minimum of -13°C (8°F) and an average of just 1°C (35°F), reaching a maximum of 17°C (62°F). Precipitation is slightly higher in January at 89 mm (3.5 in), also spread across 12 days, but the humidity rises to 92%. For more specific insights into January weather, you can visit Riehen weather in January.
September and February present stark contrasts in weather conditions. In September, temperatures can range from a chilly 2°C (36°F) at night to a warm 30°C (86°F) during the day, with an average of 16°C (61°F). This month sees about 69 mm (2.7 in) of precipitation over 12 days, combined with a relatively high humidity of 83%. In contrast, February experiences much cooler temperatures, with lows dropping to -13°C (9°F) and a maximum of 19°C (66°F), averaging just 4°C (39°F). Despite slightly more precipitation at 75 mm (2.9 in) over the same number of days, January is characterized by a higher humidity level of 89%. For a deeper look into February's weather, check out Riehen weather in February.
September and March present stark contrasts in weather patterns. September enjoys milder temperatures, with averages of 16°C (61°F) and maximums reaching up to 30°C (86°F), making it generally warmer than March, which has an average temperature of only 6°C (44°F) and can dip as low as -12°C (10°F). While both months experience considerable precipitation, September sees about 69 mm (2.7 in) over 12 days, whereas March has slightly more rainfall at 87 mm (3.4 in) spread over 14 days. Additionally, humidity levels are similar, with September at 83% and March slightly higher at 87%. For a more detailed look at March’s weather, visit Riehen weather in March.
When comparing the weather of September and April, notable differences emerge in temperature and conditions. September boasts a wider temperature range with a minimum of 2°C (36°F) and a maximum of 30°C (86°F), resulting in a comfortable average of 16°C (61°F). In contrast, April experiences cooler temperatures, with a minimum of -4°C (26°F) and a maximum of 26°C (80°F), leading to an average of just 10°C (50°F). Precipitation levels are somewhat similar, with September receiving 69 mm (2.7 in) over 12 days and April slightly less at 59 mm (2.3 in) over 10 days. Both months maintain high humidity levels, with September at 83% and April closely trailing at 84%. For a more detailed look at April weather, you can refer to Riehen weather in April.
The weather in September exhibits a wider range of temperatures, with minimums reaching 2°C (36°F) and maximums climbing to 30°C (86°F), compared to May, which has a slightly lower average and range, with minimums at 1°C (33°F) and maximums peaking at 31°C (87°F). However, May tends to be wetter, experiencing 126 mm (5.0 in) of precipitation over 17 days, whereas September sees 69 mm (2.7 in) spread across 12 days. The humidity levels are relatively similar, with September at 83% and May at 80%. This makes September feel slightly more humid despite its drier conditions. For a detailed look at the weather specifics, check out Riehen weather in May.
In June, temperatures typically start to rise, with minimums around 6°C (43°F) and averages reaching 19°C (66°F), peaking at a maximum of 34°C (94°F). This month also sees higher rainfall, with approximately 120 mm (4.7 in) of precipitation spread over about 16 days, while humidity remains relatively stable at 82%. In contrast, September experiences cooler temperatures, with a minimum of 2°C (36°F) and an average of 16°C (61°F), peaking at a maximum of 30°C (86°F). Although September has less precipitation at 69 mm (2.7 in), rain is still observed on about 12 days, coupled with a slightly higher humidity of 83%. For more detailed weather information for June, you can check Riehen weather in June.
In comparing the weather between September and July, September generally offers milder temperatures, with a minimum of 2°C (36°F) and an average of 16°C (61°F), whereas July sees a more significant range, with a minimum of 9°C (49°F), an average of 20°C (69°F), and highs reaching 36°C (98°F). Precipitation is higher in July, totaling 122 mm (4.8 in) over about 15 days, compared to September's 69 mm (2.7 in) spread over 12 days. Both months experience a high humidity level of 83%, making the air feel quite similar despite the temperature differences. For more detailed insights into July's weather, you can check Riehen weather in July.
In comparing the weather between August and September, we can observe a noticeable transition as summer gives way to early autumn. September experiences lower minimum temperatures, starting at 2°C compared to August's milder 7°C, and while the average temperature in September is cooler at 16°C, the maximum can still reach a warm 30°C. Conversely, August typically enjoys higher temperatures with an average of 20°C and peaks at 34°C. In terms of precipitation, September sees a reduction to 69 mm over 12 days, whereas August is wetter with 115 mm spread across 15 days, despite slightly lower humidity levels at 80% compared to September's 83%. For a detailed overview of August weather, you can check Riehen weather in August.
In comparing the weather between September and October, a noticeable shift can be seen in both temperature and precipitation. September boasts warmer temperatures, with minimums of 2°C (36°F) and maximums reaching up to 30°C (86°F), averaging around 16°C (61°F). In contrast, October brings cooler conditions, with minimums dipping to -1°C (30°F) and an average temperature of 11°C (52°F). Precipitation also increases slightly from September's 69 mm (2.7 in) over 12 days to October's 89 mm (3.5 in) across 13 days, while humidity rises to 90%. For a more detailed look at October weather in Riehen, visit Riehen weather in October.
September typically offers a broader temperature range, with lows around 2°C (36°F) and highs reaching up to 30°C (86°F), making it a more temperate month overall. In contrast, November sees considerably cooler averages, with minimum temperatures dropping to -4°C (25°F) and a max of 21°C (70°F). Both months experience comparable levels of precipitation, with September receiving 69 mm (2.7 in) and November slightly more at 73 mm (2.9 in), spread over roughly the same number of rainy days. Additionally, humidity is a bit higher in November at 88%, compared to September's 83%. For more detailed insights into November weather, you can check out Riehen weather in November.
In September, the weather is generally much warmer, with average temperatures around 16°C (61°F) and highs reaching up to 30°C (86°F). The month experiences moderate precipitation totaling 69 mm (2.7 in) over approximately 12 rainy days, accompanied by a humidity level of 83%. In contrast, December sees a significant drop in temperature, with averages around 3°C (38°F) and maximums peaking at 14°C (58°F). This month is wetter, recording 124 mm (4.9 in) of precipitation over 18 days and a higher humidity level of 90%. For more detailed information, you can check Riehen weather in December.
As September unfolds in Riehen, the transition from summer to autumn becomes palpable, characterized by a mix of mild temperatures and a hint of cooler nights. With an average temperature comfortably resting at 16°C, days can still reach a warm 30°C, while nights can dip to a brisk 2°C. This month experiences a notable increase in precipitation, with about 12 days of rain contributing to the 83% humidity that adds a refreshing sheen to the landscape. Unlike the warmer, drier months of summer, September invites the lushness of autumn's approach, making it a unique time to experience the beauty of nature. For those looking to delve deeper into the climatic nuances of this charming region, check out Riehen Climate.