Last updated: August 27, 2025
Experience the charming September weather in Basel, Switzerland, where comfortable temperatures create the perfect backdrop for exploration. With a maximum of 30°C (86°F) and an average of 16°C (60°F), the month offers a delightful transition from summer warmth to autumn's crispness. Notably, temperatures can dip to a brisk 1°C (35°F), so layers are advisable for evening adventures. Although precipitation is common with an average of 67 mm (2.6 in) over 10 days, the city's lush landscapes flourish in this humidity-rich environment, averaging 81%. Whether you're wandering through historical sites or relaxing along the Rhine, September in Basel promises a unique blend of comfort and charm.
In September, Basel, Switzerland begins to embrace the transition from the warmth of summer to the crispness of autumn. With temperatures ranging from a minimum of 1°C (35°F) to a maximum of 30°C (86°F), the city experiences a pleasant average of 16°C (60°F). This marked decline from August's summer peaks reflects the changing season, inviting locals and visitors alike to revel in the mild weather. As days grow slightly shorter and cooler, the enchanting landscapes of Basel, with their vibrant fall colors, become the perfect backdrop for outdoor activities and exploration. This month truly embodies the beauty of nature's shift, making it an ideal time to experience all that Basel has to offer.
In September, Basel, Switzerland experiences a notable shift in precipitation, with 67 mm (2.6 in) of rain falling across 10 days. This marks a decrease from the wetter summer months of May through August, which consistently recorded higher rainfall amounts, peaking at 133 mm (5.2 in) in May. As summer transitions into autumn, September’s precipitation not only lightens but also paves the way for the impending wetter months, as seen in the 92 mm (3.6 in) anticipated in October. The shorter duration of rainfall days this month indicates a pattern where heavy downpours may replace the more frequent, lighter showers of the previous months, hinting at the dynamic climatological shifts that characterize this time of year in Basel.
As summer fades into autumn, September in Basel, Switzerland, experiences a slight uptick in humidity, averaging 81%. This marks a subtle change from the drier conditions of August, where humidity dipped to 77%—the lowest in the year. Throughout the months, it’s evident that the humidity remains relatively high, with the winter months creeping back up to around 89% by October. Notably, the trend reveals a consistent pattern: as temperatures drop from the sweltering summer months, the air retains more moisture. This seasonal shift creates an ideal atmosphere for enjoying the fall scenery, making September a picturesque transitional month in Basel.
As summer fades and September arrives in Basel, Switzerland, the UV Index drops to 6, indicating a high exposure category and a burn time of 25 minutes. This marks a shift from the intense very high levels experienced in the peak summer months of June and July, where the UV Index soared to 9. The month serves as a transitional period, already signaling the approach of fall with lower UV intensity, yet still requiring sun protection during midday hours. It's essential to remain vigilant, even as UV levels decline compared to the scorching summer, ensuring your skin stays safe while enjoying the lingering warmth of early autumn. For more detailed UV predictions, check out Basel UV Index.
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As summer gracefully transitions into autumn, September in Basel shines with 323 hours of sunlight, offering a delightful balance between warmth and a hint of coolness. This month continues the trend of increasing daylight from the early months of the year, peaking in July with an impressive 413 hours. While the warm glow lingers, September's sunlight is notably less abundant than the peak summer months, yet it remains significantly brighter than the winter troughs seen in November and December. This gentle decline in daylight is a prelude to the shorter days ahead, allowing residents to savor those precious autumn moments illuminated by the fading rays of summer.
In September, Basel, Switzerland enjoys a 43% chance of sunny weather, marking a slight uptick as summer wanes. This month stands out due to a gradual increase in sunny days compared to the preceding months of August and July, which hover around 39% and 38%, respectively. As the vibrant colors of early autumn emerge, the likelihood of sunshine reflects a transition from the peak summer months, suggesting that while September may not be as sunny as spring's peak in April at 52%, it still offers plenty of opportunities for enjoying the crisp, fresh air under bright skies. With each passing month, the chance of sun generally dips, making September a delightful, albeit fleeting, opportunity for outdoor activities before the clouds of fall set in.
As September rolls into Basel, Switzerland, the rhythm of daylight begins to shift, marking a subtle transition from the long, sun-drenched days of summer. With 12 hours of daylight, this month signals a gentle decrease as the city prepares for autumn. Following the peak of 15 hours in June, July, and August, daylight gradually wanes, reminding us that the vibrant hues of fall are on the horizon. While still considerably bright compared to the winter months—where daylight dwindles to just 8 hours in December—September offers a perfect blend of lingering warmth and early signs of seasonal change, inviting residents and visitors alike to savor each sunlit moment.
As September unfolds in Basel, Switzerland, the wind whispers a gentle lullaby, with an average speed of 1.7 m/s (4 mph)—the slowest of the year. This transition marks a notable decline from the breezier months of late spring and early summer. After a moderate peak in May at 2.8 m/s (6 mph), the wind gradually tapers off, creating a calm atmosphere ideal for leisurely strolls along the Rhine. The diminishing gusts signal the arrival of autumn, inviting both locals and visitors to embrace the cozy charm of the city as the leaves begin to turn. With each passing day, the increasingly tranquil winds of September remind us of nature's serene shifts, offering a delightful prelude to the briskness of October.
Weather in Basel varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Basel, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present strikingly contrasting weather conditions. In September, temperatures range from a chilly 1°C (35°F) to a warm 30°C (86°F), with an average of 16°C (60°F), while humidity sits at a comfortable 81%. The month experiences moderate rainfall, totaling 67 mm (2.6 in) over approximately 10 days. In contrast, January sees much colder temperatures, with a minimum of -13°C (8°F) and a much lower average of 1°C (35°F), peaking at 16°C (61°F). This month has higher precipitation levels at 94 mm (3.7 in), occurring over 12 days, and humidity rises to 91%. For more details on weather specifics, check Basel weather in January.
September and February present stark contrasts in weather patterns. In September, temperatures range from a cool 1°C (35°F) at night to a warm 30°C (86°F) during the day, with an average of 16°C (60°F). This month experiences moderate rainfall of 67 mm (2.6 in) across about 10 days and maintains a relatively high humidity level of 81%. In contrast, February is much colder, with temperatures plummeting to a minimum of -14°C (7°F), peaking at a milder 18°C (65°F) and averaging only 4°C (39°F). This month sees slightly more precipitation at 77 mm (3.0 in) over 12 days, accompanied by even higher humidity at 89%. For more specific details about February weather, check out Basel weather in February.
When comparing the weather in September and March, it's clear that each month has its own distinct characteristics. September features a wider temperature range, with minimums around 1°C (35°F) and maximums reaching up to 30°C (86°F), contributing to an average temperature of 16°C (60°F). The month sees moderate precipitation at 67 mm (2.6 in), occurring over about 10 days, and the humidity levels hover around 81%.
In contrast, March is significantly cooler, with temperatures dipping as low as -13°C (9°F) in the early part of the month, rising to a maximum of 21°C (71°F) for an average of 6°C (43°F). It experiences higher precipitation at 91 mm (3.6 in) spread over 15 days, and slightly higher humidity at 87%. For more detailed insights, you can check out Basel weather in March. Overall, while September leans towards warmth and moderately dry conditions, March is characterized by its chilliness and increased rainfall.
September and April present distinct weather patterns that highlight the transition between seasons. In September, temperatures range from a low of 1°C (35°F) to a warm high of 30°C (86°F), with an average of 16°C (60°F), making it generally warmer than April. In contrast, April experiences cooler temperatures, with a minimum of -4°C (25°F) and a peak of 26°C (79°F), resulting in a milder average of 10°C (50°F). Both months see similar levels of precipitation, around 62 to 67 mm (2.4 to 2.6 inches), and approximately 10 days of rainfall, but September’s higher average temperatures create a more humid feel at 81%, compared to April’s 84%. For more details about April weather, you can visit Basel weather in April.
When comparing the weather in September and May, both months experience similar maximum temperatures, peaking around 30°C (86°F) in September and 30°C (87°F) in May. However, September tends to be warmer overall with an average temperature of 16°C (60°F) compared to May's cooler average of 13°C (56°F). In terms of precipitation, May is significantly wetter, receiving 133 mm (5.2 in) over 17 days, while September has less rainfall at 67 mm (2.6 in) on 10 days. Humidity levels remain quite comparable, with September at 81% and May slightly lower at 80%. For a detailed look at the weather specifics during May, visit Basel weather in May.
When comparing the weather in September and June, several notable differences emerge. September showcases a wider temperature range, with minimums dropping to 1°C (35°F) and maximums reaching up to 30°C (86°F), giving it an average temperature of 16°C (60°F). In contrast, June is slightly warmer, with a minimum of 5°C (42°F), an average of 19°C (66°F), and maximums that can rise to 34°C (94°F). Rainfall is also more significant in June, with 125 mm (4.9 in) spread over 16 days, compared to September's 67 mm (2.6 in) over 10 days; both months have similar humidity levels around 81-82%. For more detailed information on June weather, you can visit Basel weather in June.
In comparing the weather between September and July, notable differences emerge. September offers a cooler temperature range with minimums dropping to 1°C (35°F) and average temperatures around 16°C (60°F), while July boasts warmer conditions with minimums of 8°C (47°F) and averages of 20°C (68°F). The maximum temperatures in July can reach as high as 37°C (98°F), significantly warmer than September's peak of 30°C (86°F). Additionally, July experiences more rainfall, with 117 mm (4.6 in) over 14 days compared to September's 67 mm (2.6 in) over 10 days. Both months have high humidity, but September’s average humidity remains slightly lower at 81% compared to July's 82%. For those looking for a deeper dive into July's weather specifics, Basel weather in July provides comprehensive information.
In comparing the weather between August and September, we see notable differences in temperature and precipitation. August typically experiences warmer temperatures, with minimums around 6°C (43°F) and maximums reaching 35°C (95°F), resulting in an average of 20°C (68°F). Conversely, September brings cooler conditions, with minimum temperatures dropping to 1°C (35°F) and maximums at 30°C (86°F), averaging 16°C (60°F). Additionally, September receives less rainfall, with 67 mm (2.6 in) over 10 days, compared to August's 115 mm (4.5 in) over 15 days. Humidity levels are slightly higher in September at 81%, while August maintains a more comfortable 77%. For a detailed look at weather patterns, check Basel weather in August.
September and October present a notable shift in weather patterns. In September, temperatures range from a minimum of 1°C (35°F) to a maximum of 30°C (86°F), with an average of 16°C (60°F). The month experiences 67 mm (2.6 in) of precipitation spread over 10 days, with humidity levels at 81%. In contrast, October sees cooler temperatures with a minimum of -1°C (30°F) and a maximum of 24°C (76°F), averaging 11°C (51°F). It also brings more precipitation, totaling 92 mm (3.6 in) over 14 days, accompanied by higher humidity at 89%. This transition heralds the onset of autumn, making October a significantly wetter and cooler month compared to the previous one. For more details on October weather, you can visit Basel weather in October.
In September, the weather is generally warmer, with temperatures ranging from a minimum of 1°C (35°F) to a maximum of 30°C (86°F) and an average of 16°C (60°F). The month experiences about 67 mm (2.6 in) of precipitation over 10 days, accompanied by a humidity level of 81%. In contrast, November sees a significant drop in temperatures, with minimums dipping to -4°C (25°F) and an average of just 5°C (41°F). The maximum temperature reaches 21°C (70°F), but the overall climate is much cooler, with increased precipitation of 79 mm (3.1 in) over 13 days and higher humidity at 89%. For more details, you can check Basel weather in November.
September and December present markedly different weather conditions. In September, temperatures range from a mild minimum of 1°C (35°F) to a pleasant maximum of 30°C (86°F), with an average of 16°C (60°F). The month sees around 67 mm (2.6 in) of precipitation over approximately 10 days, accompanied by a humidity level of 81%. In contrast, December brings cooler temperatures, with a minimum of -5°C (23°F) and a maximum of 14°C (57°F), averaging just 3°C (38°F). The precipitation increases significantly to 129 mm (5.1 in), occurring over 19 days, while humidity rises to 91%. For more details about clothing and activities suitable for the colder month, check out Basel weather in December.
As summer gracefully transitions into autumn, September in Basel showcases a delightful blend of warm days and cool evenings. With maximum temperatures reaching up to 30°C (86°F), the month retains a sense of summery bliss, yet the average cools down to a comfortable 16°C (60°F). This shift marks a departure from the intense heat of July and August, introducing a refreshing chill that can dip to 1°C (35°F) at night. September also experiences a moderate precipitation amount of 67 mm (2.6 in) over about 10 days, contributing to the lush greenery that surrounds this charming city. The humidity, peaking at 81%, adds a gentle weight to the air, enhancing the overall cozy vibe. As the season changes, September in Basel invites travelers to enjoy its unique weather while exploring the city's vibrant culture. For further insights, visit Basel Climate.