Last updated: August 21, 2025
September in Kumamoto, Japan offers a warm transition into autumn, boasting a maximum temperature of 34°C (93°F) and an average of 24°C (76°F), while cooling down to a minimum of 14°C (57°F) at night. However, the month is also marked by considerable rainfall, with a total of 171 mm (6.7 in) spread over 14 days, contributing to a high humidity level of 84%. This combination of warmth and moisture creates a lush atmosphere, ideal for experiencing the vibrant colors of early autumn in this picturesque region.
In September, Kumamoto transitions gracefully from the summer heat, with temperatures offering a comfortable mix of warmth and mildness. The minimum dips to a pleasant 14°C (57°F), while the average rises to a cozy 24°C (76°F). Daytime highs still reach a toasty 34°C (93°F), reminiscent of August, but the overall climate starts to feel more temperate as autumn approaches. This month reflects a careful balance between the lingering warmth of summer and the coolness of the forthcoming season, making September an inviting time to explore Kumamoto’s vibrant landscapes and cultural heritage.
September in Kumamoto sees a noteworthy dip in precipitation, with 171 mm (6.7 in) of rain falling over 14 days. Following the intense downpours of summer, particularly July's peak of 406 mm (16.0 in), September presents a transition into the milder autumn months. This reduction in rainfall, while still significant, marks a shift from the heavy summer rains, allowing for slightly drier conditions as the region prepares for October. Despite this decrease, September remains a month of substantial moisture, contributing to the lush landscape typical of Kumamoto during this season. The balance of wet and dry days continues to play an essential role in supporting the area's vibrant ecology and agricultural practices.
As summer transitions into autumn, September in Kumamoto, Japan, sees a drop in humidity to 84%, a slight yet significant decrease from the oppressive levels of July and August, when humidity peaks at 92% and 91% respectively. This dip signals a welcome relief after months of sweltering conditions, where the humidity consistently hovered above 90% during peak summer. Interestingly, September's humidity levels remain fairly high compared to the earlier months of the year, reflecting a lingering moisture in the air from the hot summer months. As the year progresses toward October, humidity continues to ease slightly, suggesting that Kumamoto embraces a subtle yet refreshing shift, paving the way for the more comfortable autumn climate.
As summer fades in Kumamoto, Japan, the September UV Index remains notably high at 11, categorizing it as extreme and allowing for a burn time of just 10 minutes. This trend reflects a continuation of the intense exposure seen during the preceding months, particularly August, which peaked at 13. While September does see a slight decrease from the sweltering summer, it still demands vigilance as the risk for UV-related harm persists. As October approaches, residents and visitors alike can expect a significant drop to an index of 8, transitioning back to a very high level. Given the patterns through the year, it's clear that UV awareness is essential, especially during these high-stakes months. For more details on UV exposure throughout the year, check out the comprehensive guide here: Kumamoto UV Index.
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September in Kumamoto, Japan, offers a delightful transition as summer gives way to autumn. With 251 hours of sunshine, it stands out as a vibrant month, showcasing a decline from August's peak of 294 hours, yet still surpassing the months preceding it. This trend highlights a gradual decrease in daylight as the year progresses, following a summer filled with bright, sunny days. Notably, September's sunshine surpasses the earlier months of the year, maintaining a warm and inviting atmosphere as residents and visitors alike embrace the beauty of early fall. The lingering warmth combined with a rich display of autumnal colors makes September a truly enchanting time in Kumamoto.
As summer gives way to autumn, September in Kumamoto offers a 34% chance of sunny weather, marking a slight increase from the low percentages seen during the peak of summer months like July and August. While this isn't the sunniest month on record, it signals a gradual shift towards clearer skies, a welcome change from the much drearier days of June, which sees only a 22% chance of sunshine. After a string of less favorable months, September's sun chance is complemented by the promising outlook of October, where the likelihood jumps significantly to 63%. This transition highlights a trend towards more pleasant weather as the year progresses, making September a potential sweet spot for outdoor activities in Kumamoto.
In Kumamoto, Japan, September marks a transitional phase in daylight duration, offering about 12 hours of daylight. This month sees a gentle decline from the summer peak of 14 hours in July and June, as daylight gradually shortens with the approach of autumn. Following a vibrant summer, where longer days encouraged outdoor activities, September serves as a reminder of the changing seasons. As daylight hours decrease, a cozy atmosphere envelops the city, heralding the beauty of fall while still providing ample light for both adventure and reflection before the days grow even shorter in October. This rhythmic ebb and flow of daylight not only shapes the daily life of Kumamoto but also highlights the natural beauty of each season.
As September unfolds in Kumamoto, Japan, the wind begins to whisper with a gentle embrace, averaging 2.1 m/s (5 mph)—a subtle decline that mirrors the transition into autumn. This marks a noticeable shift from the summer months, where wind speeds hovered around 2.5 m/s (6 mph), creating a dynamic atmosphere full of life and warmth. In contrast, the winds of June, peaking at 1.7 m/s (4 mph), were notably tamer, providing a delicate backdrop to the lush, vibrant landscapes. As the year progresses, the slightly brisk breezes of September serve as a reminder of the changing seasons, bridging the lively warmth of summer to the crispness of fall, while maintaining a soothing consistency that lingers into October and November.
Weather in Kumamoto varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Kumamoto, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present strikingly different weather patterns. In September, temperatures range from a comfortable 14°C (57°F) to a warm 34°C (93°F), with an average of 24°C (76°F), accompanied by high humidity at 84%. This month also sees substantial rainfall, totaling 171 mm (6.7 in) over about 14 days. In contrast, January experiences a significant drop in temperature, with a minimum of -3°C (27°F) and a maximum of 17°C (63°F), averaging just 6°C (44°F). Precipitation in January is much lower, at 63 mm (2.5 in) across 8 days, with a lower humidity level of 75%. For more detailed information, visit Kumamoto weather in January.
September and February present stark contrasts in weather conditions. September sees warmer temperatures, averaging around 24°C (76°F) with highs reaching up to 34°C (93°F), while February's average hovers at a chilly 7°C (45°F), with maximums peaking at 19°C (66°F). The humidity in September is notably high at 84%, contributing to a humid feel, whereas February experiences a more manageable hue of 71% humidity. Precipitation also varies, with September receiving a substantial 171 mm (6.7 in) over about 14 days compared to February's 105 mm (4.2 in) across 11 days. For a more detailed look at February weather, visit Kumamoto weather in February.
In September, temperatures are significantly warmer, ranging from a minimum of 14°C (57°F) to a maximum of 34°C (93°F), with an average of 24°C (76°F). The month also experiences high humidity at 84% and considerable rainfall, accumulating 171 mm (6.7 in) over approximately 14 days. In contrast, March offers cooler temperatures, with a minimum of 1°C (34°F), an average of 11°C (52°F), and a maximum of 22°C (72°F). The precipitation in March is slightly lower at 143 mm (5.6 in) but also spans 14 days, and the humidity is more moderate at 71%. For more detailed information on March weather, visit Kumamoto weather in March.
September and April present contrasting weather patterns, each with its unique characteristics. In September, temperatures range from a minimum of 14°C (57°F) to a maximum of 34°C (93°F), with an average temperature of 24°C (76°F). The month is marked by high humidity at 84% and significant rainfall, totaling 171 mm (6.7 in) over 14 days. In contrast, April experiences cooler conditions, with temperatures from a minimum of 3°C (38°F) to a maximum of 26°C (79°F) and an average of 15°C (59°F). Rainfall is lighter, amounting to 135 mm (5.3 in) over just 9 days, and humidity is slightly lower at 78%. For more detailed insights about April weather, check Kumamoto weather in April.
In comparing the weather of September and May, September typically enjoys warmer temperatures, with an average of 24°C (76°F) and highs reaching up to 34°C (93°F), while May has cooler averages at 19°C (67°F) and maximums of 28°C (83°F). Despite being cooler, May experiences slightly more rainfall at 207 mm (8.1 in) over 12 days compared to September's 171 mm (6.7 in) over 14 days. Both months share the same humidity level of 84%, contributing to a consistently muggy atmosphere. For more detailed insights into May weather, you can check out Kumamoto weather in May.
In comparing the weather between September and June, both months exhibit warm temperatures, with September experiencing slightly higher maximums reaching up to 34°C (93°F) compared to June's peak of 30°C (87°F). The average temperature in September stands at 24°C (76°F), just above June's 23°C (73°F). However, September tends to be wetter, with 171 mm (6.7 in) of precipitation over 14 days, while June sees more rainfall at 280 mm (11.0 in) across 15 days. Humidity levels are quite similar, at 84% in September and 86% in June, creating a muggy atmosphere in both months. For a more detailed look at June weather specifically, you can check out Kumamoto weather in June.
When comparing the weather in September and July, September tends to be slightly cooler, with average temperatures ranging from a minimum of 14°C (57°F) to a maximum of 34°C (93°F), while July has higher minimum temperatures, ranging from 18°C (64°F) to an average of 26°C (79°F). However, July experiences significantly more rainfall, with 406 mm (16.0 in) over 17 days compared to September's 171 mm (6.7 in) over 14 days. Humidity levels are also higher in July at 92%, compared to September's 84%. For more details on July weather, you can check Kumamoto weather in July.
In comparing the weather patterns of August and September, it is clear that September experiences slightly cooler temperatures, with an average of 24°C (76°F) compared to August's warmer average of 27°C (82°F). The minimum temperature in September dips to 14°C (57°F), while August begins at a higher minimum of 19°C (67°F). Additionally, September sees a reduction in overall precipitation, measuring 171 mm (6.7 in), compared to August's higher 238 mm (9.4 in), although both months share the same number of rainy days at 14. Humidity levels are also slightly lower in September at 84% versus August's higher 91%. For more detailed information on August weather, you can refer to Kumamoto weather in August.
In September, the weather is generally warmer, with average temperatures reaching a comfortable 24°C (76°F) and highs peaking at 34°C (93°F). However, this warmth comes with considerable moisture, as evidenced by 171 mm (6.7 in) of precipitation over 14 days, contributing to a humidity level of 84%.
In contrast, October sees a notable drop in temperatures, with averages around 19°C (67°F) and maximums of 30°C (87°F). The month is also drier, with 117 mm (4.6 in) of rainfall over just 9 days and a slightly lower humidity level of 83%. For more detailed information, you can check out Kumamoto weather in October.
In September, the weather tends to be warmer with an average temperature of 24°C (76°F), peaking at a high of 34°C (93°F) during the day. This month experiences considerable precipitation, with 171 mm (6.7 in) spread over 14 days, resulting in a humid environment with humidity levels around 84%.
In contrast, November brings a notable drop in temperatures, with an average of 13°C (56°F) and maximums reaching 24°C (76°F). Precipitation decreases significantly to 76 mm (3.0 in) over just 9 days, and humidity levels moderate slightly to 81%. For more detailed insights into November’s weather, you can check Kumamoto weather in November.
September and December showcase contrasting weather patterns. In September, temperatures range from a minimum of 14°C (57°F) to a maximum of 34°C (93°F), with an average of 24°C (76°F). This month is characterized by high humidity at 84% and significant rainfall, totaling 171 mm (6.7 in) over 14 days. In contrast, December experiences much cooler temperatures, with a minimum of 0°C (32°F), an average of 8°C (47°F), and a maximum of 22°C (71°F). Precipitation is notably lower, with 84 mm (3.3 in) over just 9 days, and the humidity decreases slightly to 79%. For a more detailed insight into December weather, visit Kumamoto weather in December.
As September transitions in Kumamoto, it marks a shift towards cooler temperatures, with a blend of warm days and refreshing nights that stand out from the hotter summer months. While the average temperature remains pleasant, the frequent rainfall—spanning about half the month—adds a touch of humidity that enhances the lush landscape. This month serves as a reminder of the impending change in seasons, as the bustling summer energy gives way to a more tranquil ambiance. For a deeper dive into what to expect through the year, explore the full insights at Kumamoto Climate.