September Weather in Treasure Island, United States

Last updated: February 24, 2025

In September, Treasure Island, United States, experiences a delightful coastal climate characterized by an average temperature of 27°C (82°F), with highs reaching up to 32°C (89°F) and lows dropping to about 23°C (74°F). While visitors enjoy the warmth, they should also prepare for precipitation, as the area receives around 143 mm (5.6 in) of rainfall over 18 days during the month. The humidity level hovers at 78%, contributing to the lush, tropical atmosphere that defines this beautiful destination. Whether basking in the sun or savoring a refreshing rain shower, September offers a unique blend of warmth and moisture perfect for beachgoers and nature enthusiasts alike.

September Temperature in Treasure Island

In September, Treasure Island, United States begins to shift from the sultry summer months to moderately warm autumn. With minimum temperatures around 23°C (74°F) and an average of 27°C (82°F), the island maintains a tropical feel as it edges closer to fall. The maximum temperature, peaking at 32°C (89°F), still allows for plenty of sun-soaked days perfect for outdoor activities. This month marks a seamless transition, as temperatures start to dip compared to the highs of July and August, while still promising pleasant conditions for beachgoers and nature lovers alike. Overall, September offers a delightful balance of warmth and comfort, ideal for those looking to explore the natural beauty of the area before the cooler months set in.

September Weather in Treasure Island: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Treasure Island, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec626568737781828281787065
Data source: Temperature data for Treasure Island 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 Treasure Island

In September, Treasure Island experiences a significant transition in precipitation, with 143 mm (5.6 in) of rainfall spread over 18 days. This marks a notable decrease from the wetter months of July and August, which saw 204 mm (8.0 in) and 219 mm (8.6 in), respectively. Despite this reduction, September still stands as one of the wetter months of the year, hinting at the lingering effects of summer storms. As the season shifts toward autumn, the frequency of rainy days begins to taper off, paving the way for the drier months ahead. This trend underscores a gradual easing of the summer’s intense wetness, setting the stage for more moderate weather patterns as the year draws to a close.

September Precipitation Trends in Treasure Island

The chart displays monthly precipitation patterns in Treasure Island, 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.
JanFebMarAprMayJunJulAugSepOctNovDec40502060105174204219143674666
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Treasure Island

As September arrives in Treasure Island, the humidity levels see a modest increase, rising to 78% after the warmth of summer. This slight uptick from the 74% experienced in both July and August reflects the transitional nature of the month as the weather begins to shift towards fall. Interestingly, September's humidity is quite similar to the levels seen earlier in the year, particularly in April and March, indicating a recurring pattern in the region's climatic conditions. As the year progresses, humidity peaks again in the late fall and winter months, highlighting the area’s characteristic tendency toward higher moisture content, particularly in November and December. Overall, this rhythmic fluctuation underscores Treasure Island's unique coastal climate, offering a blend of warmth and humidity that resonates with both locals and visitors alike.

September Average Humidity in Treasure Island

This chart illustrates the average monthly humidity levels in Treasure Island, 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 Treasure Island

In September, the UV Index in Treasure Island remains robust at 11, categorizing it as extreme, which means you can only be exposed for about 10 minutes before risking a sunburn. This marks a continuation of the peak UV trends seen over the summer months, with July and August also recording an index of 12. As the year progresses towards autumn, it's noteworthy that while the index slightly dips in October to 9, September's intensity underscores the necessity for sun protection even as the season changes. To stay informed and prepared, check out the detailed forecasts at Treasure Island UV Index.

Maximum UV Index Levels in Treasure Island for September

The chart shows the monthly maximum UV Index (UVI) for Treasure Island 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: Treasure Island 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 Treasure Island

As September graces Treasure Island with its warm embrace, the sun shines brightly for 311 hours, marking a delightful transition from the vibrant summer months that reached their peak in May with 335 hours of sunlight. This slight dip from August’s 316 hours signals the onset of fall, yet the sun remains a cherished companion, ensuring that outdoor adventures can continue unabated. Following the trend of longer days during the summer, September retains a significant share of daylight, continuing a gradual decline leading into the shorter days of October, which offers 300 hours. This consistent sunshine fosters an inviting atmosphere for locals and visitors alike, who savor the lingering warmth before the cooler autumn breezes settle in.

Monthly Sunshine Duration in Treasure Island: September Highlighted

The September sunshine duration represents the total number of hours Treasure Island 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: Treasure Island September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Treasure Island During September

As September rolls in, Treasure Island experiences a 33% chance of sunny weather, marking a continuation of the summer's decline in sunshine. Compared to the peak months of April and May, which boast chances exceeding 60%, September shows a noticeable drop in clear skies. This downward trend carries through from the summer months, where July and August see low probabilities of sun at 23% and 17% respectively. As the fall season approaches, the likelihood of sunny days begins to improve once again with October rising to 51%. Overall, while September may present challenges for sun-seekers, the promise of clearer days returns just around the corner.

Percentage of Sunny Days in September in Treasure Island

The chart illustrates the percentage of sunny days in Treasure Island 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 Treasure Island experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec38%51%54%63%59%18%23%17%33%51%55%57%
Data source: Treasure Island September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Treasure Island in September

As September unfolds in Treasure Island, the days begin to shorten, offering 12 hours of daylight, a slight decrease from the sun-drenched summer months. This shift marks a transition from the peak of summer, where June, July, and August basked in 13 hours of sunlight, providing ample time for outdoor activities. The gradual decline in daylight starts to hint at the approaching autumn, echoing the trend seen earlier in the year. In contrast to the brisk brightness of spring, which saw 12 to 13 hours of daylight in March and April, September gracefully maintains a balance, still offering significant hours of sunshine while ushering in the cooler, crisp air of fall. As the month progresses, the transition continues, leading us to October with its rich, golden hues and 11 hours of daylight.

Average Daylight Hours in Treasure Island for September

The chart illustrates the variation in daylight duration in Treasure Island throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 35m11h 12m12h12h 50m13h 31m13h 51m13h 40m13h 4m12h 16m11h 27m10h 45m10h 23m
Data source: Treasure Island daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Treasure Island

As the summer winds down in Treasure Island during September, the average wind speed delicately drops to 3.4 m/s (8 mph), marking the calmest month of the year. This gentle breeze is noticeably lighter compared to the lively winds of late spring and early summer, which consistently hovered around 5.0 m/s (11 mph). The transition into autumn signals a shift in both temperature and wind dynamics, as the preceding months of June and July experienced even calmer conditions with average speeds of 4.1 m/s (9 mph) and 3.8 m/s (9 mph), respectively. Interestingly, after September, wind speeds begin to pick up again, indicating a seasonal momentum that brings back the refreshing gusts of fall.

Average September Wind Speed in Treasure Island

The chart displays monthly wind speed patterns in Treasure Island, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.95.34.95.05.04.13.84.23.4 m/s4.65.03.6
Data source: Treasure Island September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Treasure Island Compares to Other Months

The weather in Treasure Island 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 Treasure Island and find detailed weather information for every month.

In September, the weather is warm and humid, with average temperatures around 27°C (82°F) and highs reaching up to 32°C (89°F). The month experiences substantial rainfall, totaling 143 mm (5.6 in) over approximately 18 days, contributing to a humidity level of 78%. In contrast, January brings a cooler climate with average temperatures dropping to 17°C (62°F) and maximums around 24°C (75°F). Rainfall is significantly reduced in January, with only 40 mm (1.6 in) over about 4 days, while humidity remains relatively high at 82%. For more details about January weather, visit Treasure Island weather in January.

September and February present a stark contrast in weather conditions. In September, temperatures are significantly warmer, with a minimum of 23°C (74°F) and average highs reaching up to 32°C (89°F). The month also sees considerable rainfall, with 143 mm (5.6 in) spread over 18 days, accompanied by a high humidity level of 78%. In contrast, February experiences much cooler temperatures, with minimums dropping to 9°C (48°F) and an average high of 25°C (78°F). Precipitation is also considerably lower, totaling 50 mm (2.0 in) over just 5 days, while humidity remains relatively high at 82%. For a detailed look at conditions during this time, you can check Treasure Island weather in February.

September and March present quite contrasting weather patterns. In September, temperatures are typically warm, with a minimum of 23°C (74°F) and an average of 27°C (82°F), reaching up to a maximum of 32°C (89°F). However, this month also sees significant rainfall, accumulating 143 mm (5.6 in) over 18 days, contributing to a high humidity level of 78%. In contrast, March features much cooler temperatures, with a minimum of 8°C (46°F) and an average of 20°C (68°F), reaching a maximum of 26°C (80°F). Precipitation is notably lower in March, with only 20 mm (0.8 in) falling over just 3 days, while humidity remains slightly higher at 79%. For more detailed insights, check out Treasure Island weather in March.

When comparing the weather in September to that of April, one can observe distinct differences in temperature and precipitation. September experiences warmer temperatures, with a minimum of 23°C (74°F), an average of 27°C (82°F), and a maximum of 32°C (89°F). In stark contrast, April boasts a cooler minimum temperature of 12°C (54°F), an average of 23°C (73°F), and a maximum of 28°C (83°F). Additionally, September is significantly wetter, with 143 mm (5.6 in) of precipitation over 18 days, compared to April's 60 mm (2.4 in) over just 7 days. Interestingly, both months share the same humidity level of 78%, contributing to a similar muggy feel despite the variations in temperature and rain. For more details on the April weather, you can check out Treasure Island weather in April.

When comparing the weather in September and May, September tends to be warmer and more humid. September boasts a minimum temperature of 23°C (74°F) and averages around 27°C (82°F), reaching a maximum of 32°C (89°F), while May features slightly cooler temperatures with a minimum of 18°C (64°F), an average of 25°C (77°F), and a high of 30°C (87°F). Additionally, September experiences more precipitation, with 143 mm (5.6 in) over 18 days, compared to May's 105 mm (4.1 in) over just 10 days. Humidity levels are quite similar, with September at 78% and May at 76%. For those interested in a more detailed view of the weather conditions, you can check Treasure Island weather in May.

In comparing the weather between September and June, we find that both months experience similar temperature ranges, with minimums around 23°C (74°F), averages near 27°C (81°F), and maximums hitting 32°C (89°F). However, September tends to be slightly wetter, with a total precipitation of 143 mm (5.6 in) over 18 days, compared to June's 174 mm (6.8 in) over 19 days. Humidity levels are also notably different, with September at 78% and June slightly lower at 75%. For more detailed information on June weather specifics, you can check Treasure Island weather in June.

When comparing the weather in September and July, we can see some notable differences. September features slightly cooler temperatures, with a minimum of 23°C (74°F) and an average of 27°C (82°F), compared to July, which has a minimum of 25°C (77°F) and an average of 28°C (82°F). Both months experience similar maximum temperatures, reaching around 32°C (90°F) in July and 32°C (89°F) in September. However, September sees considerably more rainfall, accumulating 143 mm (5.6 in) over 18 rainy days, while July has heavier precipitation at 204 mm (8.0 in) across 25 days. Interestingly, September's humidity is slightly higher at 78% compared to July's 74%. For more detailed information on July weather, you can check Treasure Island weather in July.

In comparing the weather between August and September, we see some notable differences. September experiences slightly lower temperatures, with a minimum of 23°C (74°F) compared to August's 25°C (77°F). The average temperature in September is also a bit cooler at 27°C (82°F) versus August's 28°C (83°F). While both months see a maximum temperature of 32°C (89°F in September and 90°F in August), September has a significantly lower precipitation level at 143 mm (5.6 in) over 18 days, in contrast to August’s 219 mm (8.6 in) over 25 days. Interestingly, September is also more humid, averaging 78% compared to August's 74%. For a more detailed look at August weather specifically, visit Treasure Island weather in August.

In September, the weather is characterized by higher temperatures, with a minimum of 23°C (74°F) and an average of 27°C (82°F), peaking at 32°C (89°F). The month is also marked by significant rainfall, accumulating 143 mm (5.6 in) over 18 days, while humidity hovers around 78%. In contrast, October brings a noticeable drop in minimum temperatures to 15°C (59°F) and a slightly lower average of 26°C (79°F), with maximums reaching 31°C (87°F). Precipitation decreases significantly to 67 mm (2.6 in) over just 10 days, and humidity remains relatively stable at 79%. For more detailed information about daily conditions, check out Treasure Island weather in October.

In September, the weather tends to be warm and humid, with temperatures ranging from a minimum of 23°C (74°F) to a maximum of 32°C (89°F), and an average temperature of 27°C (82°F). This month also sees significant rainfall, with 143 mm (5.6 in) of precipitation spread over 18 days. In contrast, November offers a much cooler climate, with temperatures dropping to a minimum of 12°C (54°F) and a maximum of 28°C (83°F), averaging around 21°C (70°F). Additionally, November experiences significantly less rainfall, totaling just 46 mm (1.8 in) over only 6 days. Humidity remains relatively high in both months, but September feels much more oppressive due to the combination of heat and moisture. For a detailed look at the weather conditions in November, you can check out Treasure Island weather in November.

In September, the weather is characterized by warm temperatures, with nighttime lows averaging around 23°C (74°F) and daytime highs reaching up to 32°C (89°F). The month is quite rainy, experiencing about 143 mm (5.6 in) of precipitation over 18 days, along with high humidity levels of 78%. In contrast, December offers a much cooler climate, with minimum temperatures dropping to around 7°C (45°F) and maximums reaching 25°C (77°F). Precipitation significantly decreases to 66 mm (2.6 in) over just 6 days, while humidity rises slightly to 84%. For more detailed information on December weather, you can check Treasure Island weather in December.

Compare Treasure Island's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Treasure Island

As September graces Treasure Island, the weather begins to shift, offering a unique blend of warmth and humidity that sets it apart from other months. With temperatures typically hovering around a warm 27°C (82°F), it’s a great time for beachgoers, though the increased precipitation, averaging 143 mm over approximately half the month, presents a more unpredictable atmosphere. The higher humidity levels, around 78%, create a tropical feel that often contrasts sharply with the drier, cooler months that follow. Hence, while September can be a delight for sun-seekers, it also calls for a touch of adaptability in plans. For a deeper dive into what to expect throughout the year, check out Treasure Island Climate.