Last updated: August 27, 2025
In September, Ko Si Chang, Thailand, experiences a warm tropical climate characterized by a maximum temperature of 32°C (89°F) and an average of 28°C (83°F), making it an inviting destination for travelers. The minimum temperature hovers around a comfortable 25°C (78°F). However, be prepared for significant rainfall, as the island sees approximately 250 mm (9.8 in) of precipitation over 25 days. Humidity levels remain high at 87%, creating a lush environment but also necessitating a degree of acclimatization for visitors. Whether seeking adventure or relaxation, September offers a vibrant atmosphere amidst the island’s natural beauty.
In September, Ko Si Chang experiences a pleasant climate, with temperatures ranging from a minimum of 25°C (78°F) to a maximum of 32°C (89°F). The average temperature hovers around 28°C (83°F), offering a warm yet comfortable atmosphere for both tourists and locals alike. As the transition to autumn begins, September shows a slight dip in minimum temperatures compared to the preceding months, reflecting a gradual cooling trend after the summer heat. Despite this, the island maintains its inviting warmth, making it an ideal time for beach activities and exploration. Overall, September in Ko Si Chang balances warmth with a gentle breeze, perfect for enjoying the island's stunning natural beauty.
In September, Ko Si Chang experiences a significant peak in precipitation, with an impressive 250 mm (9.8 in) of rainfall, marking it as the wettest month of the year. This spike is accompanied by an increase in rainy days, totaling 25, which contributes to the island's lush and vibrant landscape. As summer transitions into the monsoon season, this trend showcases a dramatic leap from August’s already high levels of 138 mm over 22 days. This month not only highlights the island's dynamic climate but also underscores the seasonal transformation, preparing the lush scenery for the drier months ahead. Following September, the rainfall begins to taper slightly in October, yet remains substantial, demonstrating how the monsoon continues to shape the region well into autumn.
In September, the humidity in Ko Si Chang, Thailand, hovers around a substantial 87%, continuing the trend of high humidity seen throughout the summer months. The island experiences a gradual increase from 61% in March to the peak of 88% in August, reflecting the sweltering heat of the monsoon season. As the year progresses, the humidity begins to decline, with October showing a slight drop to 83%. This pattern indicates that September serves as a transitional month, where the lingering warmth meets the nearing relief of cooler, drier days ahead. Overall, the consistently high humidity underscores Ko Si Chang's tropical climate, making it a vibrant yet moist destination for visitors.
In September, Ko Si Chang, Thailand, experiences a UV Index of 13, categorized as extreme, with a burn time of just 10 minutes. This month continues the trend of high UV levels that have dominated since March, reflecting the region's sun-soaked climate. As summer transitions into autumn, the UV index remains quite formidable, similar to the previous summer months. It's essential for visitors and residents alike to take necessary precautions against sun exposure throughout this period. For detailed insights and health recommendations, check the Ko Si Chang UV Index.
UV Risk Categories
September in Ko Si Chang, Thailand, embraces a transitional phase with 267 hours of sunshine, signalling a shift as the tropical summer begins to wane. While this marks the lowest sunlight of the year, it still offers a vibrant glow, perfectly complementing the breezy coastal ambiance. The month follows a steady decline from the sun-drenched days of peak summer, where hours surged to 336 in March and hovered around 321 in April, before gradually tapering off. This gentle decrease continues into October with 284 hours, evoking a serene atmosphere perfect for exploring the island's beaches and lush landscapes. Although September may not boast the highest levels of sunlight, its rich offerings provide a unique charm, inviting both relaxation and adventure amid fading summer rays.
When considering a visit to Ko Si Chang in September, it's important to note the likelihood of sunny weather during this month is quite low, sitting at just 10%. This marks a significant decline in sunshine compared to other months, particularly the preceding spring where the chances hover around 59% to 75%. As the summer progresses into the rainy season, the opportunity for clear skies diminishes sharply, with July and August offering a mere 12% and 10%, respectively. Consequently, if you're dreaming of soaking up the sun on this idyllic island, it may be wise to explore other months, especially those in the early and late portions of the year when the sunshine rates return to more favorable levels.
In Ko Si Chang, Thailand, September marks a continuation of the vibrant 12 hours of daylight that has characterized the region's late spring and summer months. This consistent daylight duration reflects a harmonious rhythm of nature, providing ample sunlight and warm temperatures that invite outdoor exploration and activities. As summer transitions into fall, the island enjoys a remarkable balance, maintaining this 12-hour daylight period even as it edges into the cooler months of October. This trend emphasizes the tropical climate's stability, where evenings gradually lengthen while still embracing the lingering brightness of summer.
In September, the winds in Ko Si Chang, Thailand, tend to soften, with an average speed of 3.4 m/s (8 mph), marking one of the calmest months of the year. Following a lively summer where wind speeds peaked in June at 4.8 m/s (11 mph), the breeze begins to taper off as the region transitions into the softer tones of autumn. This gentle wind creates a serene atmosphere, perfect for leisurely explorations of the island's quaint beaches and vibrant landscapes. Observing the trend, it’s evident that the months preceding September showcase brisker winds, providing a refreshing contrast to the more tranquil breezes that characterize this time of year. As the winds shift, they bring a hint of anticipation for the cooler months ahead, inviting both relaxation and exploration.
Weather in Ko Si Chang varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Ko Si Chang, focusing on differences in temperature, rainfall, humidity, and UV levels.
September's weather is characterized by high temperatures, with a minimum of 25°C (78°F) and an average of 28°C (83°F), peaking at 32°C (89°F). The month is marked by significant rainfall, totaling 250 mm (9.8 inches) over 25 days, contributing to a high humidity level of 87%. In contrast, January offers a more temperate climate, featuring a minimum temperature of 18°C (64°F) and an average of 27°C (81°F), with a maximum reaching 31°C (89°F). Precipitation drops dramatically to 24 mm (0.9 inches) over only 3 days, and humidity decreases to a more comfortable 59%. For more detailed information on January weather, you can visit Ko Si Chang weather in January.
September and February present contrasting weather patterns. In September, temperatures range from a minimum of 25°C (78°F) to a maximum of 32°C (89°F), with an average of 28°C (83°F). The month is characterized by high humidity at 87% and significant rainfall, totaling 250 mm (9.8 in) spread over 25 days. In stark contrast, February enjoys milder weather with temperatures between 21°C (70°F) and 32°C (89°F), averaging 27°C (82°F). This month experiences minimal precipitation of just 19 mm (0.7 in) over only 4 days and a much lower humidity level of 58%. For a detailed look at February weather, you can visit Ko Si Chang weather in February.
In comparing the weather of September and March, we see notable differences in temperature, precipitation, and humidity. September experiences slightly higher temperatures with an average of 28°C (83°F) and can reach up to 32°C (89°F), while March has a similar average of 29°C (84°F) but overall feels a bit cooler due to lower humidity levels. Notably, September is characterized by heavy rainfall, accumulating about 250 mm (9.8 in) over roughly 25 days, compared to a much drier March, which sees only 38 mm (1.5 in) over just 7 days. Additionally, humidity is significantly higher in September at 87%, while March offers a more comfortable 61%. For more details on specific weather conditions during March, you can visit Ko Si Chang weather in March.
In comparing the weather between September and April, we see notable differences in temperature, precipitation, and humidity. September experiences a minimum temperature of 25°C (78°F) and an average of 28°C (83°F), with maximum temperatures reaching 32°C (89°F). This month is characterized by high precipitation, totaling 250 mm (9.8 in) over about 25 days, alongside a high humidity level of 87%. In contrast, April tends to be warmer with a minimum of 22°C (71°F) and maximum temperatures peaking at 34°C (93°F), while the average sits at 29°C (85°F). Precipitation decreases significantly to 100 mm (3.9 in) over 14 days, and humidity is notably lower at 70%. For more details on the weather specific to April, you can refer to Ko Si Chang weather in April.
September and May present distinct weather patterns, highlighting the transition from the height of summer to the onset of cooler autumn days. In September, the temperatures range from a minimum of 25°C (78°F) to a maximum of 32°C (89°F), with an average of 28°C (83°F). This month is characterized by high humidity at 87% and significant rainfall, totaling 250 mm (9.8 in) over approximately 25 days. In contrast, May sees slightly warmer temperatures, with a minimum of 23°C (74°F), an average of 29°C (85°F), and a higher maximum of 34°C (93°F). Precipitation in May is lower, at 160 mm (6.3 in) across 19 days, with humidity at a more moderate 80%. For more insights on the weather conditions in May, you can visit Ko Si Chang weather in May.
In comparing the weather in September and June, both months experience similar maximum temperatures around 32°C (90°F), but September tends to have slightly lower minimum temperatures, averaging 25°C (78°F) compared to June’s 26°C (80°F). June is generally a bit drier with only 99 mm (3.9 in) of precipitation over 21 days, whereas September sees a significant increase in rainfall, accumulating 250 mm (9.8 in) over 25 days. Humidity levels are comparable, with September at 87% and June at 85%. For more details on the weather in June, check out Ko Si Chang weather in June.
When comparing the weather in September and July, both months exhibit high temperatures, with average temperatures hovering around 28°C (83°F) in September and 29°C (84°F) in July. However, September tends to feature slightly cooler minimum temperatures, starting at 25°C (78°F) compared to July's 26°C (79°F). A notable difference lies in precipitation, with September receiving significantly more rain at 250 mm (9.8 in) over 25 days, while July has a total of 134 mm (5.3 in) across 23 days. The humidity remains relatively similar, at 87% in September and 86% in July, contributing to the overall tropical feel. For a detailed overview of weather conditions specific to July, you can visit Ko Si Chang weather in July.
September's weather shows a slight increase in temperature, with average highs reaching 32°C (89°F) compared to August's maximum of 31°C (89°F). However, September is characterized by significantly higher precipitation, measuring 250 mm (9.8 in) over 25 days, compared to August's 138 mm (5.4 in) across 22 days. Humidity levels remain high in both months, with September at 87% and August at 88%. For more detailed insights on August conditions, you can check Ko Si Chang weather in August.
In comparing the weather of September and October, we notice that both months exhibit similar average temperatures, with September recording a minimum of 25°C (78°F), an average of 28°C (83°F), and a maximum of 32°C (89°F), while October shows a slightly lower minimum of 24°C (76°F) but maintains the same average and maximum temperatures of 28°C (82°F) and 32°C (91°F) respectively. Precipitation levels see a minor decrease, with September experiencing 250 mm (9.8 in) over 25 days, compared to October's 232 mm (9.1 in) over 22 days. Additionally, humidity is slightly lower in October at 83%, down from September's 87%. For more detailed insights into October weather patterns, visit Ko Si Chang weather in October.
In September, the weather is characterized by slightly warmer temperatures, with a minimum of 25°C (78°F) and an average high reaching 32°C (89°F). The month is also quite rainy, receiving significant precipitation of 250 mm (9.8 in) over 25 days and high humidity at 87%. In contrast, November sees a minor dip in minimum temperatures to 23°C (74°F) but still maintains a similar average temperature of 28°C (82°F). Rainfall decreases dramatically to 56 mm (2.2 in) over just 11 days, and humidity drops to a more comfortable 78%. For a detailed overview of November's weather, you can visit Ko Si Chang weather in November.
September and December showcase contrasting weather patterns. In September, temperatures range from a minimum of 25°C (78°F) to a maximum of 32°C (89°F), with an average of 28°C (83°F). The month is characterized by high humidity at 87% and significant rainfall, totaling 250 mm (9.8 in) over 25 days. In sharp contrast, December experiences milder temperatures, with a minimum of 18°C (64°F) and a maximum of 32°C (91°F), giving an average of 27°C (81°F). The precipitation drops dramatically to just 28 mm (1.1 in) over only 3 days, and humidity decreases to 70%. For a more detailed look at the weather in December, visit Ko Si Chang weather in December.
As September unfolds in Ko Si Chang, the island experiences a distinct shift in weather patterns compared to other months. With an average temperature around 28°C, this period is characterized by high humidity levels reaching 87%, creating a tropical atmosphere that feels both warm and steamy. Rainfall is at its peak, often drenching the island on about 25 days, with a total precipitation amount of 250 mm. This abundance of moisture not only brings a refreshing change but also transforms the landscape into a lush paradise. If you're looking to understand more about the weather nuances and how they compare throughout the year, check out Ko Si Chang Climate.