Last updated: August 27, 2025
In September, Unterseen, Switzerland showcases a unique blend of mild temperatures and frequent rainfall. Daytime highs reach up to 23°C (73°F), providing a pleasant environment, while evenings cool down to an average of 11°C (53°F). The month sees a notable minimum temperature of 0°C (32°F), highlighting the crispness of late summer transitioning into autumn. Rainfall is prevalent, with an average of 124 mm (4.9 in) spread across approximately 14 days, contributing to a humidity level of 83% that enhances the lush, vibrant scenery of the region. This dynamic weather makes September an intriguing time to experience the natural beauty of Unterseen.
In September, Unterseen, Switzerland, begins to transition from the warmth of summer to the crispness of autumn. With nightly temperatures dropping to a chilly 0°C (32°F), the average temperature settles at a comfortable 11°C (53°F), making this a pleasant time for outdoor activities. The daytime highs, reaching up to 23°C (73°F), still allow for enjoyable sunny afternoons, but the noticeable shift toward cooler evenings begins to hint at the upcoming fall. This month embodies a blend of lingering warmth and the early whispers of winter, striking a balance that invites both exploration and relaxation amid the beautiful Swiss landscape.
In September, Unterseen experiences a transitional shift, with precipitation measuring 124 mm (4.9 in) over 14 rainy days. This amount aligns closely with the summer's rainfall patterns, suggesting a lingering influence of late-season weather systems. As the region moves into autumn, the precipitation levels begin to stabilize from the wetter months of June and July, which recorded significantly higher totals. While September's rainfall is slightly reduced compared to the preceding months, it serves as a reminder of nature's persistent rhythm, setting the stage for October's average of 138 mm (5.4 in). The declining number of rainy days, down from the summer peak, hints at cooler and crisper days ahead, as the landscape prepares for the winter ahead.
In September, Unterseen experiences a moderate humidity level of 83%, which is a slight increase from the 80% noted in August. This gradual rise in humidity marks a transition from summer to autumn, where moisture levels typically begin to creep upwards as the air cools and the leaves start to change. Interestingly, this month stands out as the last dip before a return to the higher humidity levels of fall and winter, with the figures surging to 90% in October. Overall, the trend reveals a gradual decrease in humidity from the wet winter months through summer, followed by a modest uptick as cooler weather approaches, illustrating the region's distinct seasonal shifts.
As summer transitions into fall, September in Unterseen, Switzerland sees a noticeable dip in the UV Index, settling at 7—a high exposure category. This marks a return to safer sun exposure conditions compared to the peak summer months when the UV Index soared to a maximum of 10. While the risk of sunburn still exists, with a burn time of 25 minutes, September offers a welcome reprieve for those looking to enjoy outdoor activities. It's a time to relish the beautiful autumn landscapes while remaining mindful of UV exposure. For more detailed information, check out the Unterseen UV Index.
UV Risk Categories
September in Unterseen, Switzerland, offers a delightful transition from the vibrant summer months into the crisp embrace of autumn. With 322 hours of sunshine, this month experiences a noticeable dip from the peak of July's 416 hours but still enjoys a generous amount of daylight compared to the earlier months. As summer fades, September’s sunshine creates a beautiful backdrop for both locals and visitors, inviting outdoor adventures amid the stunning alpine scenery. The gradual reduction in daylight hours hints at the upcoming seasonal change, making every sunshine-filled day in September a cherished experience before the shorter days of October settle in.
In September, Unterseen enjoys a consistent chance of sunny weather, with approximately 38% likelihood of sunshine. This marks a slight rebound from the summer months of July and August, where sunshine chances plateaued at the same rate. As the year progresses, the chances of clear skies vary, peaking in the early spring, followed by a gradual decline during mid-summer. However, as autumn approaches with October's sunny probabilities rising to 43%, September maintains a solid position, hinting at pleasant days that bridge the warmth of summer with the crispness of autumn. Overall, visitors can expect a charming blend of sunshine and transitioning seasonal beauty this time of year.
As summer fades into autumn, September in Unterseen, Switzerland witnesses a gentle shift in daylight, offering about 12 hours of sunlight. This month marks a transition from the long, sun-kissed days of summer, where daylight peaks at 15 hours, to the shorter hours that characterize the approaching winter months. The gradual decrease from the height of August reflects nature's rhythm, as days grow shorter and evenings invite a cozy ambiance. By the time October arrives with its 10 hours of daylight, it becomes clear that September serves as a vital bridge, allowing residents to savor the last whispers of summer before the chill of winter takes hold.
As September unfolds in Unterseen, Switzerland, the gentle caress of the wind reflects a calming consistency, with an average speed of 1.3 m/s (3 mph). This marks a continuation of the trend seen in the summer months, where the breezes remained mild and inviting. Unlike the brisk winds of winter and early spring, September offers a smooth transition into autumn, maintaining a serene atmosphere ideal for leisurely strolls and outdoor activities. Although the wind speed remains steady, the cooler temperatures herald a serene shift in the landscape, inviting residents and visitors alike to enjoy the enchanting beauty of the season.
Weather in Unterseen varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Unterseen, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present quite contrasting weather conditions. In September, temperatures range from a minimum of 0°C (32°F) to a maximum of 23°C (73°F), with an average of 11°C (53°F). This month experiences about 124 mm (4.9 in) of precipitation over approximately 14 days, along with a humidity level of 83%. In contrast, January is much colder, with temperatures falling between -19°C (-1°F) and a maximum of 9°C (48°F), averaging -3°C (26°F). Similar to September, January sees around 123 mm (4.9 in) of precipitation, but over just 12 days, and the humidity rises slightly to 92%. For more detailed insights, check out Unterseen weather in January.
September and February present dramatically different weather patterns. In September, temperatures range from a cool 0°C (32°F) to a comfortable high of 23°C (73°F), with an average of 11°C (53°F). This month typically experiences 124 mm (4.9 in) of precipitation over 14 days, coupled with humidity levels around 83%. In contrast, February is significantly colder, with temperatures dipping as low as -18°C (-1°F) and reaching a maximum of 14°C (58°F), averaging -1°C (31°F). Precipitation in February is slightly lower at 103 mm (4.0 in) spread over 11 days, while humidity is marginally higher at 89%. For more detailed information, you can refer to Unterseen weather in February.
September and March present strikingly different weather patterns. In September, temperatures range from a chilly 0°C (32°F) to a pleasant 23°C (73°F), with an average of 11°C (53°F), while March offers a far colder climate, with temperatures dipping as low as -23°C (-9°F) and peaking at 16°C (60°F), averaging around 2°C (36°F). Precipitation levels are similar, with September experiencing 124 mm (4.9 in) over 14 days and March slightly higher at 125 mm (4.9 in) across 15 days. Additionally, March's humidity at 87% contrasts with September's milder 83%, emphasizing the more oppressive feel of late winter compared to early autumn. For more details, see Unterseen weather in March.
September and April present distinct weather profiles, highlighting the transition from summer to autumn and winter to spring. In September, temperatures range from a minimum of 0°C (32°F) to a comfortable maximum of 23°C (73°F), with an average of 11°C (53°F). Precipitation during this month is relatively high, at 124 mm (4.9 in), falling over 14 days, while humidity hovers around 83%. In contrast, April experiences cooler temperatures, with a minimum of -12°C (10°F) and a maximum of 19°C (67°F), averaging at 5°C (42°F). Although April receives less precipitation at 94 mm (3.7 in) across 12 days, the humidity remains similar at 84%. For more details on April weather specifics, you can visit Unterseen weather in April.
The weather in September and May presents a striking contrast, with each month showcasing its own unique climate characteristics. In September, temperatures range from a minimum of 0°C (32°F) to a maximum of 23°C (73°F), averaging around 11°C (53°F). With 124 mm (4.9 in) of precipitation over 14 days, it also experiences relatively high humidity at 83%. Conversely, May tends to be slightly cooler, with temperatures fluctuating between -7°C (20°F) and 25°C (78°F) and an average of 9°C (48°F). This month sees increased precipitation at 182 mm (7.2 in) over 19 days, while humidity remains around 80%. For a closer look at May's weather specifically, check out Unterseen weather in May. Overall, September offers warmer temperatures and less rainfall compared to the wetter and cooler May.
In comparing the weather of September and June, September tends to be milder with average temperatures ranging from 11°C (53°F) to a maximum of 23°C (73°F), while June enjoys warmer days, with averages from 14°C (57°F) to a high of 29°C (85°F). Despite this, June experiences significantly more rainfall, with 225 mm (8.9 in) over 18 days, compared to September's 124 mm (4.9 in) over 14 days. Humidity levels are relatively similar, standing at 83% for September and slightly lower at 82% for June. For more detailed information about the weather during June, you can check Unterseen weather in June.
When comparing the weather in September to July, notable differences emerge. September tends to have cooler temperatures, with a minimum of 0°C (32°F) and a maximum of 23°C (73°F), resulting in an average of 11°C (53°F). In contrast, July is generally warmer, featuring a minimum of 5°C (41°F) and peaking at 29°C (84°F), with an average of 15°C (60°F). Precipitation also varies, with September receiving 124 mm (4.9 in) across 14 days, while July experiences more rain at 219 mm (8.6 in) over 18 days. Interestingly, humidity levels remain consistent at 83% in both months. For a more detailed look at the weather specifics during July, you can visit Unterseen weather in July.
September shows a noticeable shift in weather compared to August. The minimum temperatures drop significantly from 5°C (41°F) in August to 0°C (32°F) in September, while the average temperature decreases from 15°C (59°F) to 11°C (53°F). Maximum temperatures also fall from 28°C (82°F) in August to 23°C (73°F) in September. Precipitation levels are lower in September, with 124 mm (4.9 in) over 14 days, compared to a wetter August, which saw 203 mm (8.0 in) across 18 days. Humidity remains relatively high in both months, though it slightly increases from 80% in August to 83% in September, contributing to a cooler and more humid atmosphere. For more detailed weather specifics, you can check Unterseen weather in August.
September and October showcase a noticeable shift in weather patterns. In September, temperatures range from a minimum of 0°C (32°F) to a maximum of 23°C (73°F), with an average of 11°C (53°F). The month experiences 124 mm (4.9 in) of precipitation over 14 days, coupled with a humidity level of 83%. In contrast, October brings cooler temperatures, with a minimum of -4°C (26°F), an average of 7°C (45°F), and a maximum of 19°C (67°F). Despite being slightly wetter with 138 mm (5.4 in) over 13 days, October's humidity increases to 90%, reflecting a more autumnal atmosphere. For more detailed information, you can visit Unterseen weather in October.
In September, the weather features a milder climate with temperatures ranging from a minimum of 0°C (32°F) to a maximum of 23°C (73°F) and an average of 11°C (53°F). The month experiences significant precipitation, totaling 124 mm (4.9 in) over approximately 14 days, accompanied by a humidity level of 83%.
In contrast, November sees a more pronounced drop in temperatures, with a minimum of -10°C (13°F) and a maximum of 18°C (64°F), averaging around 2°C (35°F). Although precipitation decreases slightly to 97 mm (3.8 in) across 13 days, humidity rises to 88%, making the air feel even colder. For a detailed look at November weather, you can visit Unterseen weather in November.
September and December exhibit stark differences in weather patterns. In September, temperatures range from a minimum of 0°C (32°F) to a maximum of 23°C (73°F), with an average around 11°C (53°F). The month experiences a total of 124 mm (4.9 in) of precipitation over 14 days and has a humidity level of 83%. In contrast, December brings much colder conditions, with temperatures dipping as low as -13°C (8°F) and averaging around -2°C (29°F). Maximum temperatures in December reach only up to 9°C (49°F), while precipitation increases to 175 mm (6.9 in) spread over 17 days, accompanied by higher humidity at 90%. For a closer look at the December weather specifics, you can visit Unterseen weather in December.
As summer transitions into autumn, September in Unterseen showcases a unique blend of weather patterns that differentiate it from the preceding months. With temperatures peaking at a comfortable 23°C, the warmth is accompanied by an average drop to a cooler 11°C, signaling the onset of crisp fall days. However, the increase in precipitation, totaling 124 mm over 14 wet days, adds a refreshing touch to the air and elevates humidity levels to 83%. This combination of warmth and moisture creates a distinct ambiance, making September a captivating time to experience the natural beauty of Unterseen. For a deeper dive into the weather patterns, explore Unterseen Climate.