Last updated: August 27, 2025
In September, Solothurn, Switzerland, experiences a delightful transition into autumn, with temperatures ranging from a maximum of 29°C (84°F) to a comforting average of 15°C (59°F), dipping occasionally to a cool minimum of 2°C (35°F). The month is characterized by 77 mm (3.0 in) of precipitation spread over 12 days, resulting in lush landscapes and vibrant colors. With an humidity level of 81%, the air carries a refreshing crispness that makes it an ideal time for outdoor activities and exploration, enveloping visitors in the region's scenic beauty.
In September, Solothurn experiences a delightful transition from summer to autumn. With temperatures ranging from a comfortable minimum of 2°C (35°F) to a pleasant maximum of 29°C (84°F), the average temperature settles at around 15°C (59°F). This month marks a noticeable drop compared to the sweltering heights of July and August, yet it still retains a warm charm, inviting residents and visitors alike to enjoy the last vestiges of the outdoor season. As foliage begins to change, September stands out as a time of stunning natural beauty and moderate weather, perfect for exploring the rich culture and picturesque streets of this Swiss gem.
In September, Solothurn experiences a moderate drop in precipitation, totaling 77 mm (3.0 in) across 12 days. This lesser amount follows a series of comparatively wetter months, with July and August recording higher precipitation levels of 140 mm (5.5 in) and 145 mm (5.7 in) respectively. The onset of autumn brings a refreshing transition, as rainfall begins to taper off after the summer peak, allowing for more pleasant outdoor conditions. As the year progresses into October, precipitation rises again to 102 mm (4.0 in), indicating that while September offers a brief reprieve, the region prepares for the wetter months ahead.
As the warm embrace of summer begins to fade, September in Solothurn, Switzerland, witnesses a modest rise in humidity, settling at 81%. This marks a slight increase from the drier months of July and August, where humidity dipped to 82% and 77%, respectively. However, with cooler autumn winds on the horizon, the humidity levels start to converge again towards the much higher rates seen earlier in the year, reflecting the transition to the wetter months ahead. As October approaches, **average humidity levels leap back up to a notable 89%, reminding residents that the crisp air of fall is often accompanied by a return of moisture in the atmosphere.
As summer fades into autumn, September in Solothurn sees the UV Index dip to a high level of 6, with a recommended burn time of 25 minutes. This indicates a gradual transition from the extreme levels experienced in July and August, when the UV Index soared to 9. With the sun's intensity lessening slightly, residents and visitors can revel in outdoor activities while remaining mindful of sun protection. Remember, the exposure is still significant, so applying sunscreen is essential for extended outings. To learn more about daily variations, check out the detailed Solothurn UV Index.
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In September, Solothurn enjoys a bountiful embrace of sunshine with 325 hours of sunlight, marking a gentle transition as summer fades into autumn. This month reflects a slight decrease from the sun-drenched days of July and August, which boast peak sun hours of 417 and 385 respectively. The trend of increasing sunlight from the depths of winter, where January only offered 161 hours, culminates in a vibrant summer, before dipping again as the temperatures cool. As autumn begins to tinge the landscape with warm hues, September serves as a beautiful reminder of summer's lingering brilliance, inviting both locals and visitors to bask in the sunlight while it lasts.
In September, Solothurn, Switzerland, enjoys a 40% chance of sunny weather, marking a transition into the brisk beauty of autumn. This slight uptick from the summer months indicates that while the sun may be less frequent than in the peak of July and August, the early fall still offers a fair opportunity for pleasant sunny days. Notably, September's likelihood of sunshine is higher than that of October and surpasses several spring months, highlighting a trend where early autumn can still beckon outdoor enthusiasts. As nature begins to change, the balance of sun and softer light creates a picturesque setting perfect for exploring this charming Swiss town.
As September unfolds in Solothurn, Switzerland, daylight begins to wane, with the city experiencing around 12 hours of sunlight. Following the sun-drenched days of summer, where daylight peaked at a vibrant 15 hours in June, July, and August, September marks a gentle transition into the cooler months. The shortening days are a reminder of the approaching autumn, as sunlight gradually retreats to 10 hours in October and further diminishes to 8 hours by December. This rhythm of daylight underscores a beautiful natural cycle, where vibrant summer fades into the serene embrace of fall, inviting residents to enjoy the crisp air and changing leaves while still basking in ample light.
As summer transitions to autumn in Solothurn, Switzerland, September brings a gentle breeze with an average wind speed of just 1.6 m/s (4 mph). This marks a noticeable decline from the slightly more robust winds of the spring months, which hovered around 2.3 m/s (5 mph). The cooling temperatures and calming winds set the scene for the onset of fall, following a season of slightly breezier conditions in May. Overall, Solothurn's wind patterns illustrate a significant drop from the vernal strength, suggesting a serene shift in the atmosphere as nature prepares for the approaching chill of winter. As the winds calm, the beauty of the surrounding landscapes remains, inviting both residents and visitors to savor the tranquility of this picturesque Swiss town.
Weather in Solothurn varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Solothurn, focusing on differences in temperature, rainfall, humidity, and UV levels.
In comparing the weather of September and January, notable differences emerge. September experiences a wide temperature range, with minimums around 2°C (35°F) and maximums reaching up to 29°C (84°F), while January is markedly colder, with temperatures ranging from a minimum of -13°C (9°F) to a maximum of 16°C (61°F). Precipitation is slightly higher in January, totaling 97 mm (3.8 in) over 13 days compared to September's 77 mm (3.0 in) over 12 days. Additionally, January has a slightly higher humidity level at 91%, compared to September's 81%. For more specific details, you can check out this link: Solothurn weather in January.
September and February exhibit stark contrasts in weather conditions. In September, temperatures range from a cool 2°C (35°F) at night to a warm 29°C (84°F) during the day, with an average of 15°C (59°F) and a moderate humidity of 81%. The month experiences approximately 77 mm (3.0 in) of precipitation over 12 days, hinting at the transition from summer to autumn. In contrast, February brings much colder temperatures, with lows plunging to -11°C (13°F) and highs reaching only 18°C (64°F), averaging at 3°C (38°F). The humidity is slightly higher at 89%, and precipitation is comparable at 80 mm (3.1 in) over the same span of 12 days. For more detailed weather information about February, you can visit Solothurn weather in February.
In September, the weather is generally milder, with average temperatures ranging from a minimum of 2°C (35°F) to a maximum of 29°C (84°F). The precipitation is lighter at 77 mm (3.0 in) over about 12 days, making it a relatively pleasant month with lower humidity at 81%. In contrast, March tends to be much colder, with temperatures ranging from a minimum of -13°C (9°F) to a maximum of 21°C (69°F). Precipitation increases slightly to 97 mm (3.8 in) over 16 days, and humidity rises to 87%, indicating a wetter and chillier start to spring. For more detailed information, you can check Solothurn weather in March.
In comparing the weather of September and April, we see notable differences in temperature and precipitation. September offers a more moderate climate with average temperatures ranging from a minimum of 2°C (35°F) to a maximum of 29°C (84°F), while April has cooler averages, with temperatures starting at -4°C (24°F) and only reaching up to 25°C (78°F). Precipitation levels are somewhat similar, with September receiving 77 mm (3.0 in) over 12 days compared to April's 69 mm (2.7 in) over the same number of days. Both months experience high humidity, with September at 81% and April slightly higher at 84%. For more detailed information, you can visit Solothurn weather in April.
In comparing the weather between September and May, both months feature similar maximum temperatures, reaching up to 29°C (84°F) in September and slightly higher at 29°C (85°F) in May. However, September tends to be warmer overall with an average temperature of 15°C (59°F) compared to May's average of 13°C (55°F). Precipitation levels are notably higher in May, with 149 mm (5.9 in) spread over 18 days, compared to September's 77 mm (3.0 in) over just 12 days. Despite the increased rainfall in May, humidity levels remain comparable, with September at 81% and May at 80%. For a closer look at the specific weather patterns in May, you can check Solothurn weather in May.
When comparing the weather in September and June, notable differences emerge. September experiences a broader temperature range, with minimums around 2°C (35°F) and maximums reaching up to 29°C (84°F), averaging 15°C (59°F). In contrast, June boasts slightly warmer temperatures, with minimums at 5°C (41°F) and maximums soaring to 34°C (93°F), averaging 18°C (65°F). Precipitation patterns also differ, as June sees heavier rainfall, accumulating 134 mm (5.3 in) over 17 days, compared to September's 77 mm (3.0 in) across 12 days. Humidity levels are quite similar in both months, hovering around 81% in September and 82% in June. For more detailed information, you can check out Solothurn weather in June.
When comparing the weather in September and July, a few notable differences emerge. September experiences cooler temperatures, with a minimum of 2°C (35°F) and an average of 15°C (59°F), while July sees warmer conditions, starting at a minimum of 8°C (47°F) and averaging 19°C (67°F). Moreover, July reaches a maximum of 35°C (95°F), significantly higher than September's peak of 29°C (84°F). Precipitation is also more prominent in July, totaling 140 mm (5.5 in) over 15 days, compared to September's 77 mm (3.0 in) with precipitation on 12 days. Humidity levels are relatively consistent, at 81% in September and slightly higher at 82% in July. For a detailed look at July conditions, visit Solothurn weather in July.
September weather showcases a notable shift compared to August, with cooler temperatures overall. While August peaks at a maximum of 33°C (91°F) and has a higher average of 19°C (66°F), September sees a more moderate max of 29°C (84°F) and an average of 15°C (59°F). Precipitation also decreases in September, with 77 mm (3.0 in) over 12 days, compared to August's 145 mm (5.7 in) across 17 days. Additionally, September's humidity slightly increases to 81%, while August's is a bit lower at 77%. For more details, check out Solothurn weather in August.
September and October show a notable transition in weather patterns. In September, temperatures range from a minimum of 2°C (35°F) at night to a warm average of 15°C (59°F) and a high of 29°C (84°F) during the day. The month experiences around 77 mm (3.0 in) of precipitation over 12 days, with a humidity level of 81%. In contrast, October brings cooler temperatures, with minimums dropping to -2°C (28°F) and an average of 10°C (50°F), reaching a maximum of 23°C (73°F). Precipitation increases to 102 mm (4.0 in) over 14 days, coupled with higher humidity at 89%. For more detailed insights, you can check Solothurn weather in October.
September and November showcase distinct shifts in weather patterns. In September, temperatures range from a mild minimum of 2°C (35°F) to a comfortable maximum of 29°C (84°F), with an average of 15°C (59°F). The month experiences 77 mm (3.0 in) of precipitation over roughly 12 days, alongside a relatively high humidity of 81%. In contrast, November brings cooler conditions with temperatures dipping to a minimum of -5°C (24°F) and a maximum of 20°C (68°F), averaging around 4°C (40°F). Precipitation remains similar at 79 mm (3.1 in), spread over 13 days, but humidity rises to 89%, creating a distinctly colder and potentially damp atmosphere. For more details, check out Solothurn weather in November.
The weather in September offers a warm transition into autumn, with daily temperatures ranging from a minimum of 2°C (35°F) to a maximum of 29°C (84°F) and an average of 15°C (59°F). In contrast, December brings the chill of winter, with temperatures dropping significantly, featuring a minimum of -7°C (20°F), an average of 2°C (36°F), and a maximum of only 13°C (57°F). Additionally, December experiences more precipitation, totaling 130 mm (5.1 in) over 19 days, compared to September's 77 mm (3.0 in) over 12 days, and the humidity is notably higher at 91%. For more details on winter conditions, you can visit Solothurn weather in December.
As summer transitions to autumn, September in Solothurn offers a delightful mix of warmth and cooling breezes. With temperatures still reaching comfortable heights, the month stands out with its significant variability, where sunny days can quickly give way to cooler evenings. Although the average temperature begins to dip, the lingering warmth is complemented by a noticeable increase in humidity, creating a unique atmospheric blend. Rainfall sees a slight uptick, with several showery days contributing to the lush landscapes. This makes September a transformative month, as the city prepares for the changes that autumn will bring. For more insights on the region's climate, visit Solothurn Climate.