Last updated: February 24, 2025
In Sister Bay, United States, September brings a delightful transition into fall, characterized by an average temperature of 17°C (63°F), with maximum highs reaching 23°C (74°F). The cooler evenings see temperatures dropping to a minimum of 7°C (45°F), creating a refreshing contrast. Visitors can expect about 74 mm (2.9 in) of precipitation spread over 10 days, resulting in a humidity level of 79% that enhances the crisp, invigorating atmosphere. This month offers a unique blend of scenic beauty and mild weather, making it an ideal time for outdoor activities and experiencing the vibrant autumn foliage.
In Sister Bay, September marks a delightful transition into early autumn, where temperatures start to cool but remain pleasantly warm. The month experiences a minimum temperature of around 7°C (45°F), gradually rising to an average of 17°C (63°F) and peaking at 23°C (74°F). This reflects a shift from the summer warmth, providing a comfortable climate that invites both outdoor adventures and cozy gatherings. The trend showcases a significant departure from the sweltering highs of July and August, settling into a more moderate and refreshing atmosphere. As the leaves begin to change, September offers an idyllic backdrop for enjoying the scenic beauty of this charming coastal town.
September in Sister Bay sees a precipitation of 74 mm (2.9 in) over 10 days, marking a continuation of the wetter summer months while transitioning towards the fall season. This level of rainfall is consistent with the previous month, August, which also recorded 78 mm. Notably, September's precipitation is slightly lower than the typical early fall deluge but still significant enough to sustain local ecosystems. As the town braces for October, it can expect a marked increase in rainfall, reflected in the average 108 mm (4.2 in)—a reminder that the changing seasons often bring about greater precipitation patterns. Overall, September serves as a bridge in precipitation trends, balancing the lingering warmth of summer with the impending chill of autumn.
In Sister Bay, September brings a slight increase in humidity, averaging around 79%, following the drier summer months of July and August, which saw levels dipping to 75% and 76%, respectively. This gradual rise hints at the transition into autumn as the air prepares for the cooler temperatures ahead. Throughout the year, humidity remains relatively high, peaking at 91% in the coldest months of January and February, and slowly tapering to its lowest point in mid-summer. As September rolls in, residents can expect a refreshing yet still humid atmosphere, providing a comforting blend of summer warmth and early fall crispness.
As September rolls into Sister Bay, the UV Index reflects a shift towards the end of summer, settling at 7, which indicates a high exposure category. This means you can expect a burn time of about 25 minutes under the sun. While this month sees a decrease from August's peak of 9, it still requires caution for outdoor activities. Overall, September continues the trend of heightened UV levels experienced in the summer months, reminding residents and visitors alike to protect their skin. For more insights on UV levels throughout the year, check out Sister Bay UV Index.
UV Risk Categories
As summer gradually transitions to fall, September in Sister Bay continues to bask in a considerable glow, boasting 279 hours of sunshine. This transition marks a slight dip from the sun-soaked months of July and August, which peak at 364 and 334 hours, respectively. However, September still enjoys a generous amount of sunlight, ranking it among the sunnier months of the year. Following the warmth of summer, this month serves as a gentle reminder of the impending autumn, providing plenty of opportunities to explore the picturesque landscapes under a sky that glimmers with golden rays. As daylight begins to wane, the cooler breezes and vibrant foliage invite residents and visitors alike to savor the last vestiges of summer while enjoying the gradual embrace of fall.
September in Sister Bay, United States, offers a delightful chance of sunny weather, with a 55% likelihood of sun gracing the area. This makes it one of the brighter months of the year, following a successful summer season that saw July and August boasting impressive sun probabilities of 61% and 56%, respectively. As we transition from the peak summer months, the sun remains a familiar companion, providing pleasant days for outdoor activities and relaxation. While the chance of sunshine begins to dip in October, September stands out as a fantastic time to enjoy the lingering warmth of summer while embracing the beauty of early autumn.
As summer fades and autumn approaches, September in Sister Bay sees 12 hours of daylight, marking a gentle decline from the sun-drenched days of July and August, which each enjoyed 15 hours. This transition reflects the gradual shortening of days that begins in late summer and continues into the colder months. By October, daylight diminishes further to 10 hours, echoing a notable trend: the shift from longer, vibrant days to the more subdued, cozy afternoons of fall. As nature prepares for winter, September’s balanced daylight offers a last taste of summer's warmth, inviting residents and visitors alike to savor the crisp air and changing leaves.
As September arrives in Sister Bay, the average wind speed picks up to 6.7 m/s (15 mph), a refreshing change that signals the transition from the calmer summer months. This slight increase from August reflects a subtle shift in the seasonal breeze, contrasting with the gustier conditions of late autumn. Interestingly, the wind speeds fluctuate throughout the year, with a noticeable dip in July to just 4.9 m/s (11 mph), only to rise again as temperatures cool. November and December bring robust gusts, peaking at 8.6 m/s (19 mph) and 8.7 m/s (19 mph), respectively. This trend underscores the dynamic nature of Sister Bay's winds, providing a scenic backdrop for both tranquil afternoons and spirited autumn adventures.
The weather in Sister Bay 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 Sister Bay and find detailed weather information for every month.
In September, the weather is comparatively mild with temperatures ranging from a minimum of 7°C (45°F) to a maximum of 23°C (74°F), and an average of 17°C (63°F). The month experiences around 74 mm (2.9 in) of precipitation over about 10 days, alongside a relatively high humidity level of 79%. In contrast, January brings much colder conditions with temperatures plunging to a minimum of -18°C (-1°F) and peaking at just 5°C (41°F), resulting in an average temperature of -4°C (25°F). Although January has lower total precipitation of 48 mm (1.9 in) over about 9 days, the humidity increases to 91%. For those interested in the specifics of January weather in this area, check Sister Bay weather in January.
September and February exhibit stark contrasts in weather conditions. In September, temperatures range from a mild minimum of 7°C (45°F) to a pleasant maximum of 23°C (74°F), with an average of 17°C (63°F). The month sees about 74 mm (2.9 in) of precipitation over approximately 10 days, with humidity at 79%. In contrast, February experiences much colder temperatures, with a minimum of -19°C (-2°F) and a maximum of just 6°C (44°F), resulting in a frigid average of -4°C (24°F). This month receives slightly less precipitation at 57 mm (2.3 in) spread over 11 days, contributing to even higher humidity levels at 91%. For a detailed look at February weather, check out Sister Bay weather in February.
In comparing the weather between September and March, a stark contrast emerges in both temperature and overall climate conditions. September experiences a milder range of temperatures, with minimums around 7°C (45°F) and maximums reaching up to 23°C (74°F), accompanied by an average of 17°C (63°F). In contrast, March is much colder, featuring minimum temperatures plummeting to -19°C (-1°F) and maximums only reaching 7°C (45°F), yielding an average of -1°C (31°F). Precipitation levels in September are slightly higher, totaling 74 mm (2.9 in) over approximately 10 days, while March sees less precipitation at 61 mm (2.4 in) across about 9 days. Humidity is also higher in March at 87%, compared to September's 79%. For more detailed information, you can check Sister Bay weather in March.
When comparing the weather in September and April, it’s clear that September is significantly warmer. The average temperature in September reaches 17°C (63°F), with maximums of 23°C (74°F), while April's average is much cooler at just 2°C (36°F), peaking at 9°C (48°F). Additionally, September experiences 74 mm (2.9 in) of precipitation over about 10 days, while April sees slightly more rainfall at 88 mm (3.5 in) across 11 days. Humidity levels are also higher in April, averaging 87% compared to September's 79%. For a more detailed look at weather patterns in April, you can visit Sister Bay weather in April.
September and May present contrasting weather patterns, showcasing distinct seasonal characteristics. In September, the temperatures are generally milder, with averages reaching 17°C (63°F) and maximums peaking at 23°C (74°F), while May only sees an average of 6°C (44°F) with maximums at 15°C (59°F). Despite having similar precipitation days at 10, September tends to have lower rainfall at 74 mm (2.9 in) compared to May's 86 mm (3.4 in). Additionally, humidity levels are slightly higher in May at 82%, compared to 79% in September. For a closer look at May weather specifics, you can check Sister Bay weather in May.
In September, the weather typically sees a wider temperature range, with minimums around 7°C (45°F) and maximums reaching 23°C (74°F), offering a pleasant average of 17°C (63°F). This month experiences about 74 mm (2.9 in) of precipitation over approximately 10 days, maintaining a consistent humidity level of 79%.
In comparison, June features slightly cooler temperatures, with minimums at 5°C (41°F) and maximums capping at 22°C (72°F), resulting in an average of 13°C (55°F). June is wetter, with total precipitation at 91 mm (3.6 in) over about 11 days, yet it shares the same humidity level of 79%.
For a detailed look at the June weather in Sister Bay, check out Sister Bay weather in June.
In comparing the weather between September and July, September tends to be slightly cooler with temperatures ranging from a minimum of 7°C (45°F) to a maximum of 23°C (74°F), resulting in an average temperature of 17°C (63°F). In contrast, July offers warmer conditions, with temperatures starting at a minimum of 12°C (54°F) and peaking at 26°C (79°F), averaging around 19°C (67°F). Both months experience the same level of precipitation at 74 mm (2.9 in) over 10 days, but September has a higher humidity level at 79% compared to July's 75%. For a closer look at July’s weather specifics, you can visit Sister Bay weather in July.
In comparing September and August weather, September tends to feel cooler, with minimum temperatures dropping to 7°C (45°F) compared to August's milder 15°C (58°F). The average temperature in September is 17°C (63°F), while August averages higher at 20°C (68°F). Both months experience similar levels of precipitation, with September receiving 74 mm (2.9 in) over 10 days and August slightly higher at 78 mm (3.1 in) over 9 days. Humidity is also comparable, with September at 79% and August at 76%. For more details, you can visit Sister Bay weather in August.
September offers milder weather with minimum temperatures around 7°C (45°F) and an average of 17°C (63°F), making it a comfortable transition into autumn. However, it does experience some rainfall, accumulating about 74 mm (2.9 in) over approximately 10 days, with humidity levels around 79%. In contrast, October sees a notable drop in temperatures, starting with minimums dropping to 1°C (35°F) and an average of just 11°C (52°F), while the maximum reaches 20°C (68°F). The month is wetter, with precipitation rising to 108 mm (4.2 in) over 13 days, and humidity increases slightly to 83%. For more insights on the weather patterns, check this link: Sister Bay weather in October.
In September, the weather tends to be milder, with temperatures ranging from a minimum of 7°C (45°F) to a maximum of 23°C (74°F), averaging around 17°C (63°F). This month also experiences about 74 mm (2.9 in) of precipitation over 10 days, with humidity levels at 79%. In contrast, November sees a notable drop in temperatures, with a minimum of -6°C (21°F) and a maximum of 14°C (57°F), averaging only 4°C (39°F). Precipitation slightly decreases to 66 mm (2.6 in) over the same number of days, but humidity rises to 86%. For more detailed insights into the weather during this month, check out Sister Bay weather in November.
September and December present stark contrasts in weather conditions. In September, temperatures range from a mild 7°C (45°F) at night to a pleasant average of 17°C (63°F) during the day, peaking at 23°C (74°F). The month experiences about 74 mm (2.9 in) of precipitation over 10 days, with humidity at a comfortable 79%. In contrast, December brings much colder temperatures, with nighttime lows plunging to -17°C (1°F) and a chilling average of -1°C (31°F), reaching a maximum of 11°C (52°F). Precipitation is slightly less at 69 mm (2.7 in), occurring over 11 days, and the humidity rises to 87%, adding to the wintery feel. For a closer look at December's climate specifics, visit Sister Bay weather in December.
As summer transitions into fall, September in Sister Bay showcases a delightful blend of warm days and cooler nights, making it a unique time for visitors. While temperatures remain relatively mild, with averages that cool compared to the vibrant heat of summer, the increase in rainfall and humidity hints at the approaching autumn. With about ten days of measurable precipitation, the lush environment begins to transform, offering breathtaking landscapes. This month serves as a perfect reminder that nature is changing, and those keen to experience the beauty of Sister Bay can find more details on the region's climate by visiting Sister Bay Climate.