Last updated: August 21, 2025
In Aso, Japan, September brings a blend of warmth and moisture, making it a unique month to experience. The maximum temperature can soar to 33°C (92°F), while the average settles at a comfortable 23°C (73°F), offering a pleasant environment for outdoor activities. Nighttime cools down significantly, with minimum temperatures dipping to 9°C (49°F). Rain is a frequent visitor, with a substantial precipitation amount of 192 mm (7.6 in) over approximately 15 days, contributing to the region's lush landscapes. The air also feels quite humid at 84%, creating a tropical charm that characterizes Aso's September weather. Perfect for those seeking a vibrant yet serene atmosphere, this month showcases nature's beauty in full bloom.
In September, Aso, Japan experiences a delightful transition as summer wanes. With minimum temperatures dipping to around 9°C (49°F) and averages climbing to a pleasant 23°C (73°F), the days become notably milder. The maximum temperatures soar to 33°C (92°F), reminding us that summer’s warmth lingers just a bit longer. This month serves as a bridge, showcasing a beautiful juxtaposition between the last remnants of summer heat and the crisp approach of autumn. As the foliage begins to change, visitors can enjoy warm afternoons followed by cooler evenings, making September a perfect time to explore the stunning natural beauty of Aso.
In September, Aso, Japan, experiences a significant shift in precipitation patterns, receiving 192 mm (7.6 in) of rain over 15 days. This marks a notable reduction compared to the intense rainfall of July, which recorded a staggering 452 mm (17.8 in) across 21 days. Following the heavy downpours of the summer months, September's precipitation reflects a transition towards more moderate rainfall levels, heralding the onset of autumn. It sits comfortably between the lush highs of the preceding months and the drier spell anticipated in October, which averages only 122 mm (4.8 in). This gradual tapering in rain illustrates Aso's seasonal rhythm, offering a captivating glimpse into the region's vibrant climate dynamics.
In September, Aso, Japan, experiences a notable shift in humidity levels, which hover around 84%. This marks a slight decline from the peak of 92% in July and 91% in August, signaling the gradual transition from the steamy summer months toward the milder fall season. Overall, the trend shows a clear increase in humidity from the start of the year, peaking during the summer, before beginning its slow descent. As autumn approaches, the lingering humidity combined with the region's lush landscapes creates a uniquely crisp and refreshing atmosphere, perfect for exploring the natural beauty of Aso.
In September, Aso, Japan, continues to experience an extreme UV Index of 11, paralleling the high levels seen in the preceding summer months of July and August. This consistency in UV exposure, with a burn time of just 10 minutes, underscores a trend of heightened sun intensity that characterizes the early autumn season. As the year progresses into October, the UV Index will gradually decline, dropping to a very high level of 8. This shift provides a reminder of the changing seasons and the importance of sun protection. For more detailed information, explore the Aso UV Index.
UV Risk Categories
September in Aso, Japan, typically enjoys a glorious tapestry of sunshine, with the month boasting 248 hours of bright daylight. This is a slight decline from the sun-soaked days of August, which sees an impressive 294 hours of sunshine, yet still surpasses earlier months like June and July. As summer gracefully transitions to autumn, September’s sunlight reflects a consistent trend of longer days witnessed throughout the spring and summer, peaking in late summer before gently tapering off. Autumn's arrival brings a softer light but ensures that Aso still basks in the warm glow, making it a delightful time to explore the stunning landscapes.
In September, Aso, Japan experiences a 29% chance of sunny weather, marking a modest improvement compared to the summer months. This percentage reflects a gradual rise after the notably low sunshine chances in July and August, which plummet to 15% and 23% respectively. As summer fades, the likelihood of clearer skies increases, positioning September as a transitional month where residents and visitors can hope for more favorable weather. This trend continues into October, which leaps to a striking 58%, indicating a significant shift towards sunnier days as autumn sets in. Overall, while September may not boast the highest likelihood of sunshine, it does signal a welcome change after the cloudy, damp days of summer.
As summer transitions to autumn in Aso, Japan, September brings a gentle decline in daylight hours, with 12 hours of sunlight illuminating the landscape. This marks a gradual shift from the longer, sun-filled days of June and July, which boast 14 hours, to the shorter days of October and onward. Interestingly, September stands as a midpoint, offering slightly fewer hours than the vibrant month of May, yet still more than the coming winter months, where daylight dips to 10 hours in January and December. This rhythmic ebb and flow of daylight not only signals seasonal changes but also invites residents and visitors alike to enjoy the vibrant autumn hues in the enchanting backdrop of Aso.
In September, the winds in Aso, Japan, gracefully ease to an average speed of 2.0 m/s (4 mph), a gentle breath compared to the peak summer months. This slight decrease follows a trend observed since the spring, where the wind speeds steadily and subtly shifted toward a calmer atmosphere as the seasons transitioned. June marked the lowest point of the year with 1.7 m/s, but September’s breezes, while softening, still carry a hint of warmth from the lingering summer air. As autumn approaches, the overall pattern suggests a gradual winding down, preparing the landscape for the crispness of fall, yet ensuring that a steady, soothing breeze remains a comforting presence in this serene Japanese locale.
Weather in Aso varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Aso, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present quite contrasting weather conditions. In September, temperatures range from a cool 9°C (49°F) at night to a warm 33°C (92°F) during the day, with an average of 23°C (73°F). The month is characterized by significant rainfall, totaling 192 mm (7.6 in) over about 15 days, and high humidity at 84%. In stark contrast, January sees much colder temperatures, with lows plunging to -7°C (20°F) and highs barely reaching 16°C (62°F), averaging just 4°C (39°F). Precipitation drops significantly to 58 mm (2.3 in) over only 6 days, and humidity is lower at 75%. For more detailed insights on January weather, you can refer to Aso weather in January.
September and February present contrasting weather patterns. September boasts warm temperatures, with averages around 23°C (73°F) and highs reaching up to 33°C (92°F), accompanied by significant rainfall totaling 192 mm (7.6 in) over 15 days and high humidity at 84%. In stark contrast, February experiences much colder conditions, with average temperatures plummeting to 5°C (41°F) and a maximum of only 19°C (67°F). Precipitation in February is reduced to 98 mm (3.9 in) over 10 days, and the humidity is notably lower at 71%. For more details, you can check out this link: Aso weather in February.
September and March showcase contrasting weather patterns. In September, temperatures range from a mild 9°C (49°F) to a warm maximum of 33°C (92°F), with an average of 23°C (73°F). The month experiences significant precipitation, totaling 192 mm (7.6 in) across 15 rainy days, leading to high humidity levels at 84%. In contrast, March sees cooler temperatures, with a minimum of -3°C (27°F) and a maximum of 23°C (73°F), averaging around 9°C (49°F). This month has lower precipitation at 137 mm (5.4 in) over 12 days, accompanied by a more comfortable humidity level of 71%. For more insights on the weather during this time, check out Aso weather in March.
When comparing the weather in September and April, notable differences can be observed in temperature, precipitation, and humidity levels. September typically experiences warmer temperatures, with averages around 23°C (73°F) and highs reaching up to 33°C (92°F), while April sees cooler averages of 14°C (57°F) and maximums of 27°C (81°F). In terms of precipitation, September is wetter, receiving 192 mm (7.6 in) over approximately 15 days, compared to April's 135 mm (5.3 in) over 10 days. Despite being slightly drier, April's humidity level remains relatively high at 78%, just slightly less than September's 84%. For more detailed information about the weather specifics in April, check out Aso weather in April.
September and May present distinct weather patterns, showcasing the transition between summer and autumn. In September, temperatures range from a minimum of 9°C (49°F) to a maximum of 33°C (92°F), with an average of 23°C (73°F). The month experiences 192 mm (7.6 in) of precipitation over 15 days, maintaining a high humidity level of 84%. In contrast, May features milder temperatures, with a minimum of 2°C (36°F), an average of 18°C (65°F), and a maximum of 30°C (85°F). While May sees slightly higher precipitation at 209 mm (8.2 in), it tends to rain over fewer days, only 13. Both months share the same humidity level, yet the overall feel of May is cooler and slightly wetter than the warmer, more humid conditions of September. For a closer look at May weather in Aso, check out Aso weather in May.
In September, the weather features a significant range in temperatures, with lows around 9°C (49°F) and highs reaching up to 33°C (92°F), making it generally warmer during the day compared to June, which has a minimum of 11°C (52°F) and a maximum of 31°C (88°F). Both months experience high humidity, with September at 84% and June slightly higher at 86%. Precipitation is notably heavier in June, with 276 mm (10.9 in) of rainfall over 16 days, while September sees 192 mm (7.6 in) over 15 days. For more detailed insights into the June weather, you can check Aso weather in June.
When comparing the weather in September and July, notable differences emerge in both temperature and precipitation patterns. September enjoys a wider temperature range, with minimums around 9°C (49°F) and maximums peaking at 33°C (92°F), averaging 23°C (73°F). In contrast, July temperatures are consistently warmer, with minimums of 15°C (59°F) and maximums reaching 34°C (94°F), averaging 25°C (77°F).
However, July sees significantly more rainfall, totaling 452 mm (17.8 in) over 21 days, compared to September's 192 mm (7.6 in) over 15 days. This increase in rainfall contributes to a higher humidity level in July at 92%, as opposed to September's 84%. For more details about the July weather, you can check Aso weather in July.
In comparing the weather patterns between August and September, it becomes clear that September experiences cooler temperatures, with a minimum of 9°C compared to August's milder 16°C. The average temperature for September is also lower at 23°C versus 26°C in August, while both months see relatively warm maximums, though August reaches up to 35°C, higher than September's peak at 33°C. Additionally, September receives slightly less precipitation at 192 mm over 15 days compared to August's 253 mm across 16 days, indicating both months are quite wet but September is marginally drier. Humidity in September is also slightly lower at 84% compared to August's 91%. For those interested in a more detailed look at August weather, take a look at Aso weather in August.
September weather is characterized by warmer temperatures, with a minimum of 9°C (49°F) and an average of 23°C (73°F), reaching highs of 33°C (92°F). The month also experiences significant rainfall, averaging 192 mm (7.6 in) over 15 days, coupled with high humidity at 84%.
In contrast, October sees a noticeable drop in temperatures, with a minimum of 4°C (40°F) and an average of 17°C (63°F), while the maximum reaches 30°C (87°F). The precipitation decreases to 122 mm (4.8 in) over 9 days, and humidity remains relatively stable at 83%.
For more detailed insights about the weather during this transitional period, you can explore Aso weather in October.
September and November present a notable contrast in weather conditions. In September, temperatures range from a minimum of 9°C (49°F) to a scorching maximum of 33°C (92°F), with an average of 23°C (73°F). The month is characterized by higher precipitation, totaling 192 mm (7.6 in) across 15 days, coupled with elevated humidity levels averaging 84%. In stark contrast, November brings cooler temperatures, with a minimum of -4°C (25°F) and a maximum reaching 24°C (76°F), averaging 11°C (51°F). Precipitation drops significantly to 60 mm (2.3 in) over just 8 days, and humidity remains slightly lower at 81%. For more detailed insights on November weather in this region, visit Aso weather in November.
In September, the weather is warm and humid, with average temperatures ranging from a cool 9°C (49°F) at night to a scorching 33°C (92°F) during the day. This month experiences considerable rainfall, with 192 mm (7.6 in) of precipitation spread over 15 days, resulting in a humidity level of 84%. In contrast, December brings much colder temperatures, with highs averaging around 21°C (70°F) and lows dipping to -5°C (24°F). The precipitation decreases significantly to 70 mm (2.8 in) spread over just 7 days, and humidity levels are slightly lower at 79%. For more detailed insights on December weather, you can check Aso weather in December.
As September unfolds in Aso, the weather presents a unique blend that distinguishes it from the other months of the year. With temperatures still reaching a maximum of 33°C, the warmth of late summer lingers, yet the average temperature drops to a more comfortable 23°C, providing a delightful respite from the intense heat of July and August. Unexpectedly, September sees a rise in humidity to 84%, contributing to an atmosphere that feels both vibrant and lush. However, the month also brings increased rainfall, with an average of 192 mm over 15 days, marking a significant shift as the region transitions toward autumn. This combination of warmth, humidity, and precipitation creates an inviting tapestry for visitors and locals alike, making September a captivating time to experience Aso's unique climate. For more details on the weather patterns and how they shape the environment, explore Aso Climate.