Last updated: February 24, 2025
In Duck Key, United States, September offers a warm tropical climate characterized by maximum temperatures reaching 30°C (86°F) and an average of 28°C (83°F). However, visitors should brace for frequent rain, with approximately 200 mm (7.9 in) of precipitation spread over 18 days, contributing to a humid atmosphere that hovers around 76%. This combination of warmth and moisture makes September a unique time in Duck Key, ideal for those who enjoy lush landscapes and vibrant ecosystems, albeit with a chance of occasional downpours.
In September, Duck Key, United States, experiences a warm and inviting tropical climate, with minimum temperatures lingering around 25°C (77°F) and averages reaching a pleasant 28°C (83°F). The maximum temperatures typically peak at 30°C (86°F), providing a perfect backdrop for outdoor activities and soaking up the sun. Compared to the sweltering summer months of July and August, September brings a slight dip in heat, while still retaining that balmy essence that characterizes the region. This transition hints at the approaching fall, but with the warmth continuing, September remains an ideal time for visitors to enjoy the stunning surroundings and vibrant atmosphere of Duck Key.
In September, Duck Key experiences a significant surge in precipitation, registering a substantial 200 mm (7.9 in) of rainfall over 18 days. This marks it as the wettest month of the year, showcasing a stark contrast to the lighter rainfall in earlier months. The summer months, particularly May and June, also contributed to considerable rainfall, but September's deluge stands out, likely influenced by seasonal weather patterns such as tropical storms. As the year progresses towards autumn, the rainfall not only helps replenish the area's natural resources but also sets the stage for a lush and vibrant environment, attracting those eager to experience the rich flora and fauna of Duck Key.
In September, Duck Key experiences a noticeable shift as humidity levels rise to 76%, marking an increase from the summer months. This uptick indicates a transitional period, as the humidity in the preceding months reached a low of 69% in June before gradually climbing back. Following the warmer, drier summer, September signals a return to more humid conditions, reminiscent of the early year when humidity hovered around the 80% mark. As autumn approaches, the moisture in the air begins to build again, suggesting a shift that will carry through to the end of the year, where October and November will see humidity levels rising once more, echoing the patterns of late summer and early fall in this tropical paradise.
As summer begins to fade, September in Duck Key, United States, maintains an extreme UV Index of 12, mirroring the high readings of the previous months. This consistent level of intensity means that sun exposure remains a serious concern, with a rapid burn time of just 10 minutes. Comparatively, the UV Index trends for the year show an upward progression from lower values in the earlier months, with January's UV Index at 7, climbing steadily to reach its peak in June. As the sun continues to shine brightly in September, it's essential for residents and visitors alike to take precautions against harmful UV radiation. For more detailed information, you can check out the Duck Key UV Index.
UV Risk Categories
September in Duck Key brings a delightful embrace of 318 hours of sunshine, slightly less than the vibrant 348 hours of July and the lush 338 hours of August. As summer gently fades, this month still boasts a wealth of sunny days, maintaining a warm and inviting backdrop for outdoor adventures. The trend shows a gradual decline in daylight hours leading into the fall, yet September remains a radiant bridge between the peak of summer and the cooler months ahead. Visitors can enjoy the lingering warmth while taking in the stunning landscapes that make Duck Key a pristine getaway, proving that even as the days get shorter, the beauty of the sunlight remains ever captivating.
In September, the chance of sunny weather in Duck Key, United States, hovers around 35%, marking it as one of the less favorable months for sunshine compared to the earlier months of the year. As summer transitions to autumn, the likelihood of sunny days drops significantly from the peaks seen in winter and early spring, notably February and March, where the chances soar to 68% and 67%, respectively. This trend indicates that while late summer might bring some sun, it falls short of the brighter days experienced in the preceding months. As the fall season approaches, residents and visitors can expect a mix of weather patterns, with sun becoming a bit more elusive.
As September arrives in Duck Key, the island enjoys a pleasant 12 hours of daylight, striking a balance that reflects the transition from the peak summer months. After basking in the consistent 13 hours of sunshine from June through August, daylight begins to wane, signaling the approach of autumn. This gradual decline continues into October, where sunlight dips slightly to 11 hours. Interestingly, September's daylight mirrors that of the preceding April and May, suggesting a cyclical rhythm in the region's seasonal patterns. With the warm sun still embracing the Keys, it creates an enchanting backdrop for outdoor activities and relaxation before the cooler months set in.
In September, Duck Key experiences a noticeable dip in average wind speed, averaging just 3.5 m/s (8 mph), making it one of the calmest months of the year. This reduction follows the summer months, where winds hovered around 4.4 m/s (10 mph) in July and picked up slightly to 5.3 m/s (12 mph) in August. As autumn approaches, the winds that typically accompany the changing seasons don’t immediately manifest, offering a serene and tranquil atmosphere for visitors. The gentle breezes in September can create a perfect backdrop for relaxation and outdoor activities, suggesting a brief respite before wind speeds begin to rise again in late October and November.
The weather in Duck Key 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 Duck Key and find detailed weather information for every month.
In September, the weather is characterized by warm temperatures, with a minimum of 25°C (77°F) and an average of 28°C (83°F), peaking at 30°C (86°F). This month also sees considerable rainfall, with about 200 mm (7.9 in) of precipitation occurring over 18 days, contributing to a high humidity level of 76%. In contrast, January offers a much cooler climate with a minimum temperature of 11°C (52°F) and an average of 22°C (71°F), reaching a maximum of 26°C (80°F). Additionally, January experiences significantly less precipitation, totaling just 24 mm (1.0 in) over 4 days, along with a slightly higher humidity at 81%. For more details on January weather conditions, check out this link: Duck Key weather in January.
In September, the weather is warm and humid, with average temperatures around 28°C (83°F) and maximums reaching up to 30°C (86°F). This month also experiences significant rainfall, with about 200 mm (7.9 inches) of precipitation over 18 days, contributing to a sticky humidity level of 76%. In contrast, February offers a much cooler climate, with average temperatures dropping to 23°C (74°F) and maximums of 26°C (80°F). Precipitation is considerably lower in February, with only 28 mm (1.1 inches) recorded over just 5 days, and humidity levels slightly higher at 79%. For more detailed insights into February weather, check out Duck Key weather in February.
When comparing the weather in September and March, notable differences emerge. September experiences warmer temperatures, with a minimum of 25°C (77°F) and an average of 28°C (83°F), peaking at a maximum of 30°C (86°F). In contrast, March is significantly cooler, showcasing a minimum temperature of 15°C (60°F), an average of 23°C (74°F), and a maximum of 26°C (80°F). Additionally, September is much rainier, with 200 mm (7.9 in) of precipitation spread over 18 days, whereas March sees only 22 mm (0.9 in) across just 3 days. Both months share a humidity level of 76%, contributing to a consistent moisture feel in the air. For more detailed information on March weather, check out Duck Key weather in March.
When comparing September and April weather, there are notable differences in temperature, precipitation, and humidity. September tends to be warmer, with average temperatures around 28°C (83°F), peaking at 30°C (86°F), while April's average sits at a cooler 25°C (77°F) and maxes out at 29°C (84°F). Additionally, September experiences significantly higher precipitation levels with 200 mm (7.9 in) over 18 days, in stark contrast to April's 44 mm (1.7 in) over just 7 days. Humidity remains relatively similar, with September at 76% and April at 73%. For those interested in more details about April weather in Duck Key, you can check Duck Key weather in April.
In September, the weather tends to be hotter and more humid compared to May. With minimum temperatures around 25°C (77°F) and daily averages reaching 28°C (83°F), September experiences higher warmth, peaking at 30°C (86°F). This month also sees significant rainfall, averaging 200 mm (7.9 in) over approximately 18 days, resulting in a humidity level of 76%. In contrast, May has slightly cooler temperatures, with a minimum of 22°C (72°F) and an average of 26°C (79°F), topping out at 29°C (84°F). Rainfall is less frequent in May, totaling 142 mm (5.6 in) over about 11 days, and the humidity is a bit lower at 71%. For more details, check out Duck Key weather in May.
In comparing the weather between September and June, we see that both months enjoy warm temperatures, with September's minimum temperature slightly higher at 25°C (77°F) compared to June's 24°C (75°F). The average temperatures for both months are similar, hovering around 28°C (82°F) to 28°C (83°F). However, September is noticeably wetter, with a precipitation level of 200 mm (7.9 in) over 18 days, while June receives only 105 mm (4.1 in) across 16 days. Furthermore, September's humidity is higher at 76%, compared to June's 69%. For those interested in June weather specifics, you can check more details at Duck Key weather in June.
In comparison to July, September tends to be slightly cooler, with daytime temperatures averaging around 28°C (83°F), compared to July's average of 28°C (83°F), but it has higher maximum temperatures reaching up to 30°C (86°F) compared to July’s peak of 31°C (87°F). Both months experience similar minimum temperatures of around 25°C (77°F), but September is characterized by significantly higher precipitation levels at 200 mm (7.9 in) over 18 days, compared to July’s 90 mm (3.6 in) over 16 days. Additionally, September's humidity averages 76%, which is higher than July’s 70%, making the air feel muggier. For more detailed weather information on July, check the following link: Duck Key weather in July.
In comparing the weather of September and August, both months feature high temperatures, but September experiences slightly cooler averages, with a minimum of 25°C (77°F) and a maximum of 30°C (86°F), compared to August's minimum of 25°C (78°F) and maximum of 31°C (87°F). However, September sees significantly higher precipitation, with 200 mm (7.9 in) spread over 18 days, while August is relatively drier with only 96 mm (3.8 in) over 16 days. Humidity levels also rise slightly in September to 76%, compared to 72% in August. For more detailed information on August weather, visit Duck Key weather in August.
In September, the weather tends to be warmer, with minimum temperatures around 25°C (77°F) and an average of 28°C (83°F), peaking at 30°C (86°F). This month also experiences significant rainfall, totaling 200 mm (7.9 in) over 18 days, coupled with a humidity level of 76%. In contrast, October sees cooler nights with a minimum temperature of 19°C (67°F) and a slight drop in the average to 27°C (81°F), reaching a maximum of 29°C (85°F). Rainfall decreases to 131 mm (5.2 in) over the same 18 days, while humidity rises slightly to 79%. For those interested in more specifics, you can explore Duck Key weather in October.
In September, the weather tends to be warmer, with minimum temperatures around 25°C (77°F) and an average of 28°C (83°F), peaking at 30°C (86°F). This month also sees significant rainfall, averaging 200 mm (7.9 in) over 18 days, contributing to a humidity level of 76%. In contrast, November presents cooler conditions, with minimum temperatures dropping to 17°C (63°F) and an average of 25°C (77°F), reaching a maximum of 28°C (83°F). The precipitation is considerably less, at 69 mm (2.7 in) over just 11 days, while humidity increases slightly to 80%. For more detailed insights, check Duck Key weather in November.
In September, the weather is notably warmer, with average temperatures around 28°C (83°F) and maximums reaching up to 30°C (86°F). The month is also characterized by significant rainfall, with 200 mm (7.9 in) of precipitation over 18 days, resulting in a humidity level of 76%. In contrast, December offers a much cooler environment, featuring average temperatures of 23°C (74°F) and maximums peaking at 26°C (80°F). The precipitation during this month drops significantly to 44 mm (1.7 in) over just 7 days, and humidity increases slightly to 81%. For more details on December weather, you can check Duck Key weather in December.
As September settles in Duck Key, the weather begins to reveal its vibrant personality, contrasting with the summer heat. With average temperatures hovering around a comfortable 28°C (83°F), it provides a gentle transition into fall while maintaining the warm, tropical embrace that visitors cherish. However, it's also notable for its increased precipitation, experiencing a higher number of rainy days compared to previous months—perfect for those who appreciate the lush, vibrant landscape that follows. The combination of humidity at 76% adds a sultry feel that defines this month. Explore more about what to expect throughout the year at Duck Key Climate.