Last updated: February 24, 2025
September weather in Lake Geneva, United States showcases a blend of summer warmth and early autumn coolness. With maximum temperatures reaching 33°C (92°F), the month offers plenty of sunny days, balanced by an average temperature of 19°C (66°F). Visitors can expect a refreshing variety of experiences, though the mercury can dip as low as 2°C (37°F) during cooler nights. Rainfall is a factor to consider, with about 104 mm (4.1 in) of precipitation spread over 9 days, contributing to an average humidity level of 79%. This dynamic weather makes September an intriguing time for outdoor activities and scenic explorations around the lake.
As September unfolds in Lake Geneva, temperatures begin to shift from the warmth of summer to the cooler embrace of autumn. The month greets visitors with a minimum temperature of 2°C (37°F), providing a refreshing start to fall. Daytime averages hover around a comfortable 19°C (66°F), ideal for outdoor activities, while peaks can reach a balmy 33°C (92°F), reminding us of the lingering summer heat. This transitional period showcases a delightful balance, making September a perfect time to explore the scenic beauty and vibrant activities the area has to offer, before the cooler months set in. Overall, the trends indicate a gradual cooling, yet the warmth still presents opportunities for enjoying the outdoors under the crisp, clear skies.
In September, Lake Geneva experiences a notable shift as the summer heat wanes, bringing an average precipitation of 104 mm (4.1 in) over 9 rainy days. This marks a slight decrease from August's 91 mm yet remains consistent with the overall trend of increased rainfall from late spring to early fall. April stands out as the wettest month of the year, densely packed with 110 mm (4.3 in), while May tops the chart with the highest accumulation. As the region transitions into autumn, the gradual buildup of precipitation hints at the forthcoming wetter months, particularly October, which typically sees a further rise in rainfall. The overall pattern showcases a dynamic interplay between seasonal changes and precipitation levels, shaping the picturesque landscape of Lake Geneva.
In September, Lake Geneva experiences a modest humidity level of 79%, marking a slight uptick from the summer months. This increase comes after a consistent decline from the peak summer humidity, with July and August recording levels of 78% and 76% respectively. As the season shifts towards autumn, humidity begins to rise again, hinting at the upcoming cooler months. Compared to the higher levels seen earlier in the year, particularly the consistent 85% seen from January through April, September's humidity reveals the gradual transition of the region's climate. As the year progresses, residents can expect a return to higher humidity levels in the autumn months, particularly with October bringing a notable 83% humidity, reflecting the natural ebb and flow of Lake Geneva's seasonal characteristics.
As summer gives way to fall, September in Lake Geneva continues to feature a very high UV Index of 8, indicating that sun exposure remains a significant concern. With a burn time of just 15 minutes, it's critical to take precautions when spending time outdoors. This month marks a slight decline from the peak UV levels seen in July and August, which consistently registered at 10. The trend across months reveals a seasonal pattern where the UV Index rises sharply from early spring, peaking in the summer before tapering off into the milder levels of autumn. For those planning outdoor activities, staying informed about the UV Index is essential to ensure enjoyment while minimizing sun exposure risks. For more information, check out the detailed report on the Lake Geneva UV Index.
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In September, Lake Geneva basks in a beautiful 277 hours of sunshine, wrapping up the summer with a radiant farewell. This month sees a gentle decline in sunlight as it transitions from the sun-soaked highs of July at 360 hours and August with 336 hours. Typically, September offers a perfect blend of warmth and cooler breezes, making it an ideal time for outdoor activities amidst the mesmerizing fall foliage. As the days grow shorter and the sun gradually retreats, locals and visitors alike take advantage of the remaining golden rays before cooler temperatures set in, making it a truly enchanting time to experience all that Lake Geneva has to offer.
September stands out as a beacon of sunny potential in Lake Geneva, boasting a 57% chance of sunshine. This marks a noticeable uptick from the summer months, showcasing the transition towards autumn while still holding onto glimmers of warmth. As the hottest months of June and August flirt with sunny probabilities around the mid-40s, September clearly ushers in a renewed vigor for outdoor activities. The likelihood of sunshine peaks during this month, suggesting it’s an ideal time for residents and visitors alike to soak up the last rays of summer before the more overcast days of October set in. Overall, September offers a perfect blend of bright skies and comfortable temperatures, making it a delightful time to explore the scenic beauty of Lake Geneva.
As the summer slowly recedes, September in Lake Geneva heralds a shift towards shorter days, offering approximately 12 hours of daylight. This marks a gentle decline from the sun-soaked days of July, which boasted a peak of 14 hours. While August keeps the warmth alive with a similar duration, September signifies a transition, as daylight begins to wane, hinting at the impending autumn. This trend continues into October, where daylight further diminishes to 11 hours. The gradual ebb of daylight throughout the year not only paints a beautiful seasonal tapestry but also invites residents and visitors alike to savor the crisp, early fall days before the shorter, darker months of winter.
As September ushers in a gentle transition toward fall, Lake Geneva experiences a rejuvenating average wind speed of 3.4 m/s (8 mph), echoing the calmer breezes of August. This consistency in wind patterns marks a notable shift from the summer lull, where winds softened to their lowest at 2.5 m/s (6 mph). While the summer months showcase a gradual decline in wind speeds, September rejuvenates the air, paving the way for the brisk, invigorating winds that autumn will bring. Looking ahead, the winds maintain this steady pace through October before picking up again in the winter months, emphasizing the natural ebb and flow of the seasons in this picturesque region.
The weather in Lake Geneva 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 Lake Geneva and find detailed weather information for every month.
September and January present a stark contrast in weather conditions. In September, temperatures range from a minimum of 2°C (37°F) to a maximum of 33°C (92°F), with an average of 19°C (66°F). This month also sees a relatively high humidity level of 79% and experiences around 104 mm (4.1 in) of precipitation spread across 9 days. In contrast, January features a much colder climate, with temperatures dipping as low as -32°C (-25°F) and averaging -5°C (23°F), peaking at a mild 14°C (57°F). Precipitation is less frequent during this month, averaging just 61 mm (2.4 in) over 8 days, and the humidity is slightly higher at 85%. For more specifics on January conditions in the area, you can check Lake Geneva weather in January.
The contrast between September and February weather is striking. September enjoys a warm climate with average temperatures around 19°C (66°F) and highs reaching up to 33°C (92°F), making it feel quite mild despite some rain, totaling 104 mm (4.1 in) over nine days. In contrast, February presents a stark chill with average temperatures plummeting to around -4°C (25°F) and lows dipping as low as -33°C (-28°F). Although it experiences less precipitation, with 58 mm (2.3 in) over the same number of days, the increased humidity at 85% adds to the cold discomfort. For more details on February weather, see Lake Geneva weather in February.
The weather in September is characterized by a warm temperature range, with minimums of 2°C (37°F) and maximums reaching up to 33°C (92°F), averaging around 19°C (66°F). This month also sees significant rainfall, totaling 104 mm (4.1 in) over about 9 days and a relative humidity of 79%. In contrast, March experiences much colder temperatures, with lows plummeting to -22°C (-8°F) and highs peaking at 24°C (75°F). The average temperature sits at a chilly 3°C (37°F), and while it has slightly less precipitation at 66 mm (2.6 in), it occurs over a similar number of rainy days (10) and a higher humidity level of 85%. For more specific weather patterns during this month, you can check Lake Geneva weather in March.
When comparing the weather in September and April, several notable differences emerge. September boasts higher average temperatures, ranging from a chilly 2°C (37°F) at nights to a warm 33°C (92°F) during the day, while April experiences much cooler nights with a minimum of -8°C (17°F) and a daytime maximum of 27°C (81°F). Precipitation levels are relatively similar, with September receiving 104 mm (4.1 in) over 9 days, compared to April's 110 mm (4.3 in) over 14 days, indicating that April might feel a bit wetter despite the slightly higher overall totals in rain. Humidity levels are fairly close as well, with September at 79% and April slightly higher at 85%. For more specific insights about April conditions, check out Lake Geneva weather in April.
In comparing September and May weather, we see notable differences in temperature and precipitation patterns. September boasts a wider temperature range, with lows of 2°C (37°F) and highs reaching up to 33°C (92°F), while May starts colder with a minimum of -1°C (30°F) and a maximum of 34°C (93°F). Despite May's potential for warmer maximum temperatures, September offers a more stable average of 19°C (66°F), compared to May's average of 15°C (60°F). Precipitation levels in May are higher, with 154 mm (6.0 in) over 14 days, compared to September's 104 mm (4.1 in) accumulated over 9 days, leading to a relatively wetter month in May despite slightly lower humidity at 78%. For a detailed look at conditions during this time, check out Lake Geneva weather in May.
Comparing the weather in September and June reveals some notable differences. September boasts a wider temperature range, with minimums dropping to 2°C (37°F) and maximums reaching 33°C (92°F), while June maintains a more stable range with minimums at 9°C (48°F) and maximums peaking at 34°C (94°F). Precipitation is similar in both months, with September recording 104 mm (4.1 in) over 9 days and June slightly higher at 115 mm (4.5 in) over 13 days. Humidity levels are comparable as well, with September at 79% and June slightly higher at 80%. For a more detailed look at June weather in the Lake Geneva area, check out Lake Geneva weather in June.
When comparing the weather in September and July, significant differences emerge. September experiences a broader temperature range, with minimums dropping to 2°C (37°F) and maximums reaching 33°C (92°F), while averaging 19°C (66°F). In contrast, July boasts warmer temperatures, with minimums at 12°C (54°F), averages of 24°C (75°F), and maximums slightly higher at 34°C (93°F). Additionally, September has more precipitation, averaging 104 mm (4.1 in) over about 9 days, compared to July's 84 mm (3.3 in) over 10 days, making September feel slightly wetter despite having fewer total rainy days. Humidity levels are fairly comparable, with September at 79% and July at 78%. For more specific insights on July weather, check out Lake Geneva weather in July.
In comparing the weather between August and September, it is evident that September experiences a wider temperature range with minimums dropping to 2°C (37°F) compared to August's higher minimum of 8°C (47°F). While the average temperature in September is slightly lower at 19°C (66°F) versus 22°C (72°F) in August, September can still see maximum temperatures reaching up to 33°C (92°F), which is only marginally less than August's peak of 34°C (93°F). Additionally, September tends to be wetter, accumulating 104 mm (4.1 in) of precipitation over 9 days, whereas August has a total of 91 mm (3.6 in) over 11 days. Humidity levels are comparable, with September at 79% and August at 76%. For more insights on August conditions, you can refer to Lake Geneva weather in August.
September brings a warmer climate with average temperatures around 19°C (66°F) and highs reaching up to 33°C (92°F), while October experiences a significant drop in temperature, averaging only 11°C (53°F) and dipping to a minimum of -5°C (23°F). The increase in precipitation is also notable, with September seeing 104 mm (4.1 in) over 9 days, compared to October’s 119 mm (4.7 in) spread over 13 days. Humidity slightly rises from 79% in September to 83% in October, contributing to an increasingly brisk atmosphere. For a closer look at how October weather unfolds in this region, check out Lake Geneva weather in October.
September and November present stark contrasts in weather patterns. September boasts a wider temperature range, with minimums of 2°C (37°F) and maximums reaching 33°C (92°F), averaging around 19°C (66°F). In this month, precipitation is higher at 104 mm (4.1 in) over about 9 days, accompanied by a humidity level of 79%. In contrast, November sees a significant drop in temperatures, with minimums plummeting to -16°C (4°F) and maximums at 24°C (75°F), leading to a much cooler average of 3°C (37°F). Precipitation decreases to 49 mm (1.9 in) across 7 days, but humidity rises slightly to 88%. For more details on November weather, you can check Lake Geneva weather in November.
September and December present stark contrasts in weather patterns. September typically experiences milder temperatures, ranging from a minimum of 2°C (37°F) to a maximum of 33°C (92°F), with an average of 19°C (66°F). This month is characterized by higher precipitation, averaging 104 mm (4.1 in) over 9 days, and a humidity level of 79%. In contrast, December brings significantly colder weather, with temperatures plummeting to a minimum of -22°C (-7°F) and an average of -1°C (31°F). Precipitation falls to 52 mm (2.1 in) over 7 days, and humidity slightly increases to 81%. For a deeper look into December weather specifics, check out Lake Geneva weather in December.
As summer fades into autumn, September brings a delightful transition in Lake Geneva's weather, characterized by a unique blend of warmth and crispness. Unlike the scorching highs of July, September’s temperatures are notably more moderate, yet they can still soar to enjoyable peaks during the day while cooling significantly at night. With an average humidity of 79%, the air retains a refreshing quality, balanced by the occasional rains that punctuate the month, totaling around 104 mm over roughly nine days. This combination creates a picturesque setting perfect for outdoor activities, allowing visitors to relish the stunning fall scenery without the intense heat of the summer months. For more detailed insights, explore the full Lake Geneva Climate.