September Weather in Longboat Key, United States

Last updated: February 24, 2025

Discover the weather in Longboat Key during September, where temperatures typically range from a comfortable 24°C (75°F) at night to a warm 32°C (90°F) during the day, averaging around 27°C (82°F). This coastal paradise experiences about 152 mm (6.0 in) of rainfall, spread across 18 days, resulting in a humid atmosphere with an average humidity of 78%. Despite the precipitation, September remains an inviting month for beach lovers and outdoor enthusiasts seeking to enjoy the sun and vibrant local scenery.

September Temperature in Longboat Key

September in Longboat Key offers a delightful transition into autumn, characterized by warm tropical temperatures that linger from summer. With a minimum of 24°C (75°F) and reaching up to a maximum of 32°C (90°F), the month boasts an average temperature of 27°C (82°F), keeping the beach vibes alive. Notably, September's warmth closely mirrors the preceding summer months, particularly August, which also features similar highs. This consistency allows for sun-drenched days and balmy nights, perfect for enjoying outdoor activities before the cooler months set in. As summer fades, the humidity begins to ease, making September an ideal time for visitors seeking both warmth and comfort in this beautiful coastal haven.

September Weather in Longboat Key: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Longboat Key, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec636668737781828281797166
Data source: Temperature data for Longboat Key generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Longboat Key

In September, Longboat Key experiences a noticeable dip in precipitation compared to the preceding summer months, yet it remains one of the wettest times of the year. With 152 mm (6.0 inches) of rainfall over 18 days, the month sees a significant decrease from August’s 208 mm (8.2 inches), marking a transition towards the drier fall months ahead. The frequent rains can be attributed to lingering tropical weather patterns typical of late summer, although the number of rainy days reduces slightly from the previous month. Overall, September serves as a bridge, balancing the lush humidity of summer with the gradually easing weather of autumn, making it a unique period for both locals and visitors alike.

September Precipitation Trends in Longboat Key

The chart displays monthly precipitation patterns in Longboat Key, with values for each month alongside September's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec38442255101168180208152674764
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Longboat Key

September in Longboat Key sees a humidity level of 78%, marking a slight uptick from the summer months where it averaged 74%. This change hints at the transition into fall, as moisture in the air begins to rise again after the relatively drier summer. Interestingly, this September figure is close to the levels recorded in the spring, reflecting a return to more typical coastal conditions. As the year progresses, humidity spikes again in October at 79%, suggestive of the seasonal patterns that frequently influence this beautiful coastal region. Overall, Longboat Key experiences a gentle ebb and flow of humidity throughout the year, with September serving as a bridge between the warm, dry summer and the more humid months ahead.

September Average Humidity in Longboat Key

This chart illustrates the average monthly humidity levels in Longboat Key, with September's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec82%82%79%78%76%75%74%75%78%80%82%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Longboat Key

In September, Longboat Key continues to bask in intense sunshine with a UV Index of 11, marking it as an extreme exposure category. This level of ultraviolet radiation necessitates caution, as the recommended burn time is only 10 minutes. Following the summer months, which also exhibited extreme levels of UV exposure, a slight decrease in the index can be noted, yet it remains consistently high. As the region transitions into October, the UV Index lowers to 9, but for September, sun-seekers should be vigilant to protect their skin. It's essential to stay informed and safe while enjoying Longboat Key's beautiful beaches. For more details, visit Longboat Key UV Index.

Maximum UV Index Levels in Longboat Key for September

The chart shows the monthly maximum UV Index (UVI) for Longboat Key in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec6810111112121111975
Data source: Longboat Key September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Longboat Key

In September, Longboat Key enjoys a delightful 311 hours of sunshine, reflecting the tail end of summer when the days are still brilliantly bright and inviting. This month showcases a slight dip from the peak hours of sunshine experienced in May at 335 hours, yet it holds its own as one of the sunniest months of the year. As fall approaches, the gradual decrease in sunlight from August to September signals the transition to a milder climate, but it still maintains a robust amount of sunshine, ensuring plenty of opportunities for outdoor activities. Overall, the region boasts a phenomenal average of radiant days throughout the year, with sunshine hours consistently above 300 from late spring to early fall, making Longboat Key a perennial haven for sun-seekers.

Monthly Sunshine Duration in Longboat Key: September Highlighted

The September sunshine duration represents the total number of hours Longboat Key experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec216h265h321h319h335h303h319h316h311h300h279h269h
Data source: Longboat Key September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Longboat Key During September

In Longboat Key, United States, September sees a moderate chance of sunny weather, with approximately 32% likelihood of sunshine. This figure is a notable dip from the sunnier months of April and May, which boast chances of 65% and 60%, respectively. After the vibrant summer, where sun exposure significantly drops to 18% in both July and August, September offers a slight return to clearer skies but remains one of the less sunny months on the calendar. As fall approaches, residents and visitors can anticipate a blend of sun and clouds, making it a transitional month where the weather begins to cool off while occasionally delivering delightful sunny days.

Percentage of Sunny Days in September in Longboat Key

The chart illustrates the percentage of sunny days in Longboat Key throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Longboat Key experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec39%52%56%65%60%19%24%18%33%51%55%59%
Data source: Longboat Key September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Longboat Key in September

As summer fades into autumn, September in Longboat Key offers a delightful balance of daylight, averaging around 12 hours. This month marks a gentle transition from the peak summer brightness of 13 hours enjoyed in June, July, and August, gradually easing into the shorter days of October. The trend showcases a notable decrease in daylight as the year progresses, with shorter hours in October and November, ultimately returning to 10 hours by December. This rhythm of daylight not only signifies changing seasons but also invites residents and visitors to savor the beauty of sunsets as the landscape shifts toward fall.

Average Daylight Hours in Longboat Key for September

The chart illustrates the variation in daylight duration in Longboat Key throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 37m11h 13m12h12h 49m13h 30m13h 49m13h 39m13h 3m12h 16m11h 28m10h 46m10h 25m
Data source: Longboat Key daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Longboat Key

As summer transitions to fall, September in Longboat Key brings a notable dip in wind speeds, averaging just 3.3 m/s (7 mph). This marks a decline from the more robust breezes of earlier months, with July and August featuring slightly stronger winds at 3.8 m/s (8 mph) and 4.1 m/s (9 mph), respectively. The gentle September zephyrs create a serene atmosphere, perfect for leisurely beach strolls and tranquil moments by the shore. As the fall approaches, wind speeds begin to inch back up, setting the stage for a shift in the landscape as autumn unfolds. Overall, September showcases a delightful calmness, offering a peaceful respite before the winds pick up again later in the year.

Average September Wind Speed in Longboat Key

The chart displays monthly wind speed patterns in Longboat Key, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec4.85.34.85.04.94.13.84.13.3 m/s4.65.03.5
Data source: Longboat Key September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Longboat Key Compares to Other Months

The weather in Longboat 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 Longboat Key and find detailed weather information for every month.

September and January present stark contrasts in weather conditions. In September, temperatures are notably warmer, with a minimum of 24°C (75°F) and an average of 27°C (82°F), peaking at 32°C (90°F). This month also experiences significant rainfall, totaling 152 mm (6.0 in) over 18 days, alongside a humidity level of 78%. In contrast, January offers much cooler temperatures, with a minimum of 3°C (38°F), an average of 17°C (63°F), and a maximum of 24°C (75°F). Precipitation is also dramatically reduced to only 38 mm (1.5 in) over 4 days, while humidity remains relatively high at 82%. For a detailed look at the January climate, you can visit Longboat Key weather in January.

September and February showcase contrasting weather patterns. In September, temperatures are quite warm, with a minimum of 24°C (75°F) and an average of 27°C (82°F), reaching highs of 32°C (90°F). The month is also characterized by significant rainfall, averaging 152 mm (6.0 in) over 18 rainy days, coupled with a humidity level of 78%. In stark contrast, February offers a much cooler climate, with temperatures ranging from a minimum of 9°C (49°F) to a maximum of 25°C (78°F), and an average of 19°C (66°F). Precipitation is minimal during this month, with only 44 mm (1.7 in) over just 5 rainy days, and humidity slightly higher at 82%. For a closer look at February weather specifics, check out Longboat Key weather in February.

In comparing the weather of September and March, a stark contrast emerges. September boasts much warmer temperatures, with a minimum of 24°C (75°F) and an average of 27°C (82°F), peaking at a sweltering 32°C (90°F). The month is also characterized by significant rainfall, with 152 mm (6.0 in) spread over 18 days, coupled with high humidity at 78%. In contrast, March experiences milder temperatures, with a minimum of 8°C (47°F) and a pleasant average of 20°C (68°F), reaching a maximum of 26°C (79°F). Rainfall is minimal during March, with only 22 mm (0.9 in) over just 3 days, while humidity remains similar at 79%. For more detailed information on the weather patterns in March, check out Longboat Key weather in March.

When comparing the weather in September and April, it's clear that September tends to be significantly warmer and more humid. In September, temperatures range from a minimum of 24°C (75°F) to a maximum of 32°C (90°F) with an average of 27°C (82°F). Conversely, April offers a cooler climate, with temperatures ranging from a minimum of 13°C (55°F) to a maximum of 28°C (82°F) and an average of 23°C (73°F). Additionally, September experiences higher rainfall, with 152 mm (6.0 in) of precipitation spread over 18 days, while April has only 55 mm (2.2 in) over 6 days. Despite the temperature differences, both months share similar humidity levels at 78%. For a deeper look at the specifics, check out Longboat Key weather in April.

September and May offer distinct weather experiences. In September, temperatures begin at a minimum of 24°C (75°F) and peak at 32°C (90°F), with an average of 27°C (82°F). This month sees higher precipitation, totaling 152 mm (6.0 in) over 18 days, coupled with a humidity level of 78%. In contrast, May presents milder conditions, featuring a minimum temperature of 18°C (65°F) and a maximum of 30°C (87°F), averaging 25°C (77°F). Additionally, May experiences less rainfall, with only 101 mm (4.0 in) across 10 days, and slightly lower humidity at 76%. For more details, you can check Longboat Key weather in May.

Comparing the weather in September and June reveals some similarities and differences. Both months have a minimum temperature of around 24°C (75°F) and an average temperature close to 27°C (81°F), providing a warm and humid climate. However, September tends to be slightly warmer, with a maximum temperature of 32°C (90°F), compared to June's peak at 31°C (89°F). Precipitation levels are quite close, with September receiving 152 mm (6.0 in) over 18 days and June experiencing 168 mm (6.6 in) over 19 days. Additionally, September has a higher humidity level at 78%, compared to June's 75%. For more details on June's weather, you can check Longboat Key weather in June.

When comparing the weather in September and July, both months exhibit warm temperatures, but September tends to be slightly cooler. September sees minimum temperatures of 24°C (75°F) and an average of 27°C (82°F), while July has a minimum of 25°C (77°F) with a similar average of 28°C (82°F). Both months experience maximum temperatures around 32°C (90°F for September and 89°F for July). However, September is characterized by higher precipitation levels, averaging 152 mm (6.0 in) over 18 rainy days, compared to July's 180 mm (7.1 in) spread over 24 days. Humidity remains relatively similar, with September at 78% and July at 74%. For more detailed insights, you can check Longboat Key weather in July.

In comparing the weather of September and August, September tends to be slightly cooler, with an average temperature of 27°C (82°F) compared to August's 28°C (83°F). Both months maintain a maximum temperature of 32°C (90°F), but September has a slightly lower minimum temperature of 24°C (75°F) compared to August's 25°C (77°F). Additionally, September experiences reduced precipitation, with 152 mm (6.0 in) over 18 days, while August sees higher rainfall of 208 mm (8.2 in) over 25 days. Humidity levels are also slightly higher in September at 78%, compared to August's 74%. For more detailed weather conditions, you can check Longboat Key weather in August.

In comparing the weather for September and October, it is evident that October offers a significant drop in minimum temperatures, with lows of 15°C (60°F) compared to September's warmer 24°C (75°F). While the average temperatures remain relatively close, with October's average at 26°C (79°F) versus September's 27°C (82°F), October experiences less precipitation, accumulating only 67 mm (2.7 inches) over 10 days, a stark contrast to September’s 152 mm (6.0 inches) over 18 days. Humidity levels remain similar, hovering around 78% in September and 79% in October. For more detailed insights, check out Longboat Key weather in October.

September tends to be much warmer and wetter compared to November. With minimum temperatures around 24°C (75°F) and maximums reaching 32°C (90°F), September averages 27°C (82°F) while experiencing significant rainfall of 152 mm (6.0 in) over 18 days, accompanied by a humidity of 78%. In contrast, November cools down with minimum temperatures dropping to 12°C (55°F) and maximums reaching 28°C (82°F), resulting in a more comfortable average of 22°C (71°F). Precipitation decreases significantly in November to just 47 mm (1.8 in) over 6 days, coupled with a slightly higher humidity of 82%. For a closer look at the weather patterns in November, you can check Longboat Key weather in November.

In September, the weather is warm and humid, with temperatures ranging from a minimum of 24°C (75°F) to a maximum of 32°C (90°F), averaging around 27°C (82°F). This month experiences significant rainfall, with precipitation of 152 mm (6.0 in) over 18 days, leading to a humidity level of 78%. In contrast, December brings a much cooler climate, with temperatures dropping to a minimum of 8°C (46°F) and peaking at 25°C (77°F), averaging 19°C (66°F). Rainfall is less frequent in December, with only 64 mm (2.5 in) over 6 days, though the humidity remains relatively high at 84%. For more detailed information, you can check Longboat Key weather in December.

Compare Longboat Key's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Longboat Key

As summer begins to fade, September in Longboat Key brings a notable shift in the weather. While temperatures remain warm with averages hovering around 27°C (82°F), the increase in humidity at 78% and significant rainfall can make the air feel heavier, setting it apart from the drier summer months. With about 18 rainy days contributing to a total precipitation of 152 mm (6.0 in), outdoor activities might be punctuated by occasional showers. Despite these changes, September remains a beautiful time to visit, offering warm ocean waters and lush landscapes. For a comprehensive look at the region's climate throughout the year, check out Longboat Key Climate.