Last updated: February 24, 2025
September in Sisters, Oregon, offers a diverse range of weather conditions, showcasing the unique beauty of the season. With maximum temperatures soaring to 37°C (99°F), the days provide ample warmth, while the average temperature remains a comfortable 15°C (59°F). As the nights cool down, temperatures can dip to a chilly -3°C (26°F), reminding residents of the upcoming fall. Rainfall is modest, with an average precipitation of 36 mm (1.4 in) spread across 5 days, contributing to the area's lush landscape. The humidity averages around 59%, adding a slight coolness to the air and enhancing the crisp feel of autumn on the horizon.
In Sisters, Oregon, September marks a significant transition as summer begins to wane, with temperatures reflecting a gradual shift toward fall. The month starts cool with a minimum temperature dipping to -3°C (26°F), while the average settles at a pleasant 15°C (59°F)—ideal for outdoor activities amidst the changing leaves. The warmth lingers, reaching a maximum of 37°C (99°F) toward the beginning of the month, reminiscent of the sweltering summer weeks prior. This unique blend of temperature extremes not only invites locals and visitors to enjoy the crisp autumn air but also serves as a gentle reminder of the approaching cooler months. As September draws to a close, the landscape transforms, ushering in a picturesque scene vibrant with seasonal colors, setting the stage for the chillier days ahead.
In September, Sisters, United States, experiences a significant shift in precipitation patterns as the dry summer months give way to increased rainfall, totaling 36 mm (1.4 in) across 5 days. This marks a transition from the scant precipitation of July and August, where barely 6 mm (0.3 in) and 8 mm (0.3 in) fell, respectively. Compared to earlier months, such as January and February, where precipitation peaked at 93 mm (3.7 in) and 109 mm (4.3 in) over 13 and 15 days, September's rainfall is relatively modest but signals the approach of the wetter fall season. As the month unfolds, residents are reminded of the shifting climate as the landscape prepares for the lush, rainy days ahead, particularly with October bringing an anticipated increase to 43 mm (1.7 in) over 7 days.
As summer transitions into autumn, September in Sisters, United States, showcases a notable decrease in humidity, dropping to 59%. This marks a significant shift from the lush, high humidity of the earlier months, where levels frequently hovered around 80-87% from January through August. The progressive decline in humidity throughout the summer peaks in August at 62%, setting the stage for September's drier atmosphere. This trend highlights not only the changing seasons but also the comfortable conditions that residents and visitors can enjoy as the crisp air begins to settle in, paving the way for a refreshing fall experience.
As summer transitions to fall in Sisters, Oregon, September maintains a very high UV Index of 8, with a burn time of just 15 minutes. This is indicative of the lingering summer sunshine, even as daylight begins to wane. Following a peak in May with an extreme index of 11, the UV levels gradually decrease but remain significant through the month. It's a crucial reminder for outdoor enthusiasts to continue safeguarding their skin as they enjoy the vibrant autumn landscapes. For more detailed information, visit Sisters UV Index.
UV Risk Categories
As September unfolds in Sisters, United States, residents and visitors alike can bask in the warm glow of 293 sunshine hours—a vibrant finale to the summer season. Following the peak of July, with its impressive 409 hours, September gracefully transitions into autumn, showcasing a notable decrease yet still surpassing the hours of the cooler months ahead. This month acts as a gentle reminder of summer's warmth, bridging the long, sun-drenched days of June and July to the golden hues of October. The drop from the high summer peaks signals the changing seasons, but September’s sunlight remains generous, inviting outdoor adventures before the crisp autumn air takes hold.
September in Sisters, United States, boasts a promising likelihood of sunny weather, with 71% of days typically filled with sunshine. As summer transitions into autumn, the sunshine probability remains robust, only slightly dipping from the 75% seen in August. This trend highlights a consistent pattern of high sun exposure during the late summer months, making September an excellent time for outdoor activities. Compared to the dark, drizzly days of winter, where chances of sun plummet to a mere 21% in January, September shines as a beacon of warmth and light. Enjoying the tail end of summer's glow, visitors and residents alike can revel in the beautiful scenic adventures that this month has to offer.
As summer gently fades in Sisters, United States, September marks a transition with approximately 12 hours of daylight. This slight decrease from the peak of 15 hours in June and July hints at the impending shift towards autumn. The balance of day and night reflects the gradual retreat of summer’s brilliance, as daylight hours begin to shorten. Following a vibrant summer, nature prepares for the cozy embrace of fall, with October bringing even less light at 10 hours. Observing these changes can evoke a sense of nostalgia, as each sunset signals the approaching seasons and the unique beauty that accompanies them.
As summer wanes and fall approaches, September in Sisters, United States, brings a gentle whisper of wind. With an average wind speed of 2.1 m/s (5 mph), it's the calmest month of the year, reflecting a noticeable trend of gradually decreasing winds from the summer months. This slight drop, following the more dynamic breezes of June and July, suggests a transition into the tranquil rhythms of autumn. Interestingly, September’s winds mirror those of January, indicating a cyclical pattern as the region shifts towards cooler climates. As nature prepares for the upcoming seasonal changes, the soft, steady breeze invites reflection and appreciation for the beauty of this time of year.
The weather in Sisters 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 Sisters and find detailed weather information for every month.
September weather in Sisters is characterized by a wider temperature range, with daytime highs averaging around 15°C (59°F) and soaring up to 37°C (99°F), while nighttime lows can drop to -3°C (26°F). This month experiences moderate humidity at 59% and relatively low precipitation, averaging 36 mm (1.4 in) over about 5 days. In contrast, January brings much colder conditions, with average temperatures hovering around 0°C (33°F) and nighttime lows plummeting to -24°C (-11°F). The winter month also sees significantly higher precipitation, totaling 93 mm (3.7 in) over 13 days, and a notable increase in humidity at 86%. For more details on January's weather, visit Sisters weather in January.
September and February present strikingly different weather conditions. In September, temperatures range from a chilly -3°C (26°F) at night to a sweltering 37°C (99°F) during the day, with an average of 15°C (59°F). The month sees relatively low precipitation, measuring 36 mm (1.4 in) over about five days, and the humidity is a moderate 59%. In contrast, February is much colder, with temperatures dropping to as low as -22°C (-7°F) and peaking at 17°C (62°F), averaging around 0°C (33°F). This month experiences significantly more precipitation, totaling 109 mm (4.3 in) over 15 days, along with higher humidity at 87%. For more details, you can check Sisters weather in February.
In September, the weather is notably warmer, with average temperatures around 15°C (59°F) and maximum highs reaching up to 37°C (99°F). This month experiences relatively low precipitation, totaling 36 mm (1.4 in) over just 5 days, accompanied by a moderate humidity level of 59%. In contrast, March presents a cooler climate with an average temperature of 3°C (38°F), and minimum temperatures can drop to -15°C (5°F), while maximums peak at 19°C (67°F). March is also wetter, with 66 mm (2.6 in) of precipitation spread across 13 days, and the humidity is significantly higher at 86%. For more detailed insights about March weather, visit Sisters weather in March.
When comparing the weather in September and April, notable differences emerge in both temperature and precipitation. September typically presents a wider temperature range, with minimums around -3°C (26°F) and maximums reaching up to 37°C (99°F), and an average of 15°C (59°F). In contrast, April tends to be cooler, with minimum temperatures dropping to -8°C (17°F) and maximum temperatures peaking at 28°C (83°F), averaging only 7°C (45°F). Additionally, September sees less precipitation, averaging 36 mm (1.4 in) over about 5 days, while April experiences a higher total of 67 mm (2.6 in) spread across approximately 11 days. Humidity levels also differ, with September at 59% compared to April's higher 85%. For a closer look at the specific weather conditions in the area, you can refer to Sisters weather in April.
September weather generally offers a wider temperature range compared to May, with minimums reaching as low as -3°C (26°F) and maximums soaring to 37°C (99°F). The average temperature in September is a comfortable 15°C (59°F), while May experiences slightly cooler averages at 12°C (53°F) with a minimum of -5°C (23°F) and a maximum of 31°C (88°F). Both months see similar precipitation levels, with September receiving 36 mm (1.4 in) over about 5 days and May slightly more at 37 mm (1.5 in) over 8 days. Humidity also differs, with September at 59% and May notably higher at 80%. For a closer look at the weather specifics in May, you can refer to Sisters weather in May.
In comparing the weather of September and June, we see notable differences in temperature and humidity levels. September experiences a wider temperature range, with minimums dropping to -3°C (26°F) and maximums reaching as high as 37°C (99°F), resulting in an average temperature of 15°C (59°F). In contrast, June has a milder minimum temperature of 0°C (32°F) and peaks at 42°C (108°F), yielding an average of 16°C (61°F). Precipitation in June is slightly less at 22 mm (0.9 in) over 6 days, compared to September’s 36 mm (1.4 in) over 5 days, while humidity is notably higher in June at 82%, opposed to September's 59%. For more details about June weather, visit Sisters weather in June.
In comparing the weather of September and July, both months experience similar maximum temperatures, peaking at 37°C (99°F). However, September showcases a broader temperature range with a minimum of -3°C (26°F) and an average of 15°C (59°F), while July has a milder minimum of 0°C (33°F) and a higher average of 20°C (69°F). Precipitation levels also differ significantly; September receives 36 mm (1.4 in) over 5 days, contrasting sharply with July's minimal 6 mm (0.3 in) of rain across just 1 day. Additionally, September's humidity sits at 59%, noticeably lower than July's higher humidity of 78%. For a closer look at July weather, visit Sisters weather in July.
In comparing the weather between September and August, September exhibits a broader range in temperatures, with a minimum of -3°C (26°F) and a maximum that can reach up to 37°C (99°F). The average temperature in September is lower, at 15°C (59°F), compared to August's average of 20°C (68°F). Additionally, September experiences more precipitation, totaling 36 mm (1.4 in) over 5 days, while August enjoys a drier spell with only 8 mm (0.3 in) over 2 days. Humidity levels are also slightly lower in September at 59%, compared to 62% in August. For more detailed insights, refer to Sisters weather in August.
September and October showcase distinct transitions in weather patterns. In September, temperatures can range dramatically from a chilly -3°C (26°F) at night to a warm average of 15°C (59°F), peaking at a scorching 37°C (99°F). This month experiences relatively low precipitation at 36 mm (1.4 in) over about 5 days, accompanied by a moderate humidity level of 59%.
In contrast, October introduces a notable drop in temperatures, with minimums dipping to -9°C (16°F) and an average of just 8°C (47°F), while daytime highs reach a maximum of 30°C (87°F). Precipitation also increases slightly to 43 mm (1.7 in) over 7 days, and humidity rises to a higher 78%. For more details on what to expect in October, check out Sisters weather in October.
September and November exhibit striking differences in weather patterns. September experiences a wide temperature range with minimums around -3°C (26°F) and maximums peaking at 37°C (99°F), leading to a pleasant average of 15°C (59°F). In contrast, November sees much colder conditions, with lows dipping to -18°C (0°F) and a much cooler average of 3°C (38°F), while highs reach only up to 22°C (71°F). Additionally, November brings increased precipitation, with 74 mm (2.9 in) falling over 11 days, compared to September's 36 mm (1.4 in) over just 5 days, accompanied by higher humidity levels of 88% compared to September's 59%. For more detailed information about the weather patterns in November, you can visit Sisters weather in November.
September weather in Sisters is characterized by a much warmer climate, with average temperatures around 15°C (59°F) and occasional highs reaching up to 37°C (99°F). This month experiences relatively low precipitation, with only 36 mm (1.4 in) over about five days and a moderate humidity level of 59%. In contrast, December brings significantly colder conditions, with an average temperature of around 0°C (33°F) and lows dropping to -19°C (-2°F). Precipitation increases to 93 mm (3.7 in) across 14 days, and humidity rises to a crisp 88%. The stark differences in temperature, precipitation, and humidity between these two months highlight the transition from a warm early autumn to a cold winter season. For more details about the December climate in Sisters, you can visit Sisters weather in December.
In September, the weather in Sisters showcases a unique transition as summer gives way to fall. The month often features a remarkable range in temperatures, from warm days to crisp evenings, distinguishing it from the more consistent heat of July and August. With humid days peaking at 59% and only a few days of rain, September offers a delightful balance of sunshine and cooler breezes. This makes it an ideal time for outdoor activities as nature begins to don its autumn colors. For a deeper understanding of how September compares to other months, check out Sisters Climate.