Last updated: January 18, 2025
Kumamoto, Japan, is characterized by a humid subtropical climate classified under the Koppen-Geiger system as Cfa. This climate type is marked by significant seasonal variations in temperature, with a minimum recorded at -10°C (15°F) in February, contrasting sharply with the scorching maximum of 39°C (103°F) during August. The average annual temperature is a mild 17°C (62°F), indicative of the region's comfortable and diverse weather patterns that foster rich biodiversity and agricultural productivity throughout the year.
In Kumamoto, Japan, temperature patterns exhibit a distinct seasonal rhythm, transitioning from chilly winters to hot summers. January and February experience the coldest months, with minimum temperatures dipping to -10°C (15°F), while average highs only reach the low 20s Celsius. As spring unfolds in March and April, temperatures gradually rise, showcasing mild days with averages climbing from 11°C (53°F) to 15°C (60°F), and maximums reaching 29°C (84°F). The warmth intensifies through May and June, with average temperatures soaring to 20°C (67°F) and 23°C (73°F), respectively, before reaching peak summer heat in July and August, where maximums can exceed 39°C (103°F). The arrival of autumn brings a gradual cooling, with September and October showing comfortable averages in the 24°C (76°F) to 19°C (67°F) range, and frosty nights re-emerging by November and December, as temperatures dip back to single digits, signifying a return to winter conditions.
In the region of Kumamoto, temperature variations are noteworthy across different cities. Aso experiences a minimum of -8°C (18°F) in February and peaks at 35°C (96°F) in August, as detailed in monthly temperatures in Aso. Similarly, Kumamoto itself records a minimum temperature of -3°C (27°F) in January, with a maximum of 34°C (94°F) in August, highlighted in monthly temperatures in Kumamoto. Minamata presents a comparable pattern, with its temperatures ranging from -4°C (25°F) in January to 35°C (96°F) in August, as shown in monthly temperatures in Minamata.
Kumamoto experiences a highly variable precipitation pattern throughout the year, with significant rainfall concentrated during the summer months. Beginning in January, the region receives 59 mm (2.3 in) of rain over about 6 days, gradually increasing in February with 100 mm (3.9 in) as wintry conditions linger. The transition into spring results in a rise in both precipitation and rainy days, peaking in May at 216 mm (8.5 in) over 12 days, while March and April contribute moderately with 143 mm (5.6 in) and 137 mm (5.4 in), respectively.
The summer months of June and July mark the height of Kumamoto's rainy season, with precipitation surging to an impressive 294 mm (11.6 in) and 448 mm (17.6 in), respectively, accompanied by 16 and 19 rainy days. Although August sees a decline to 261 mm (10.3 in), it still represents a substantial rainfall total, followed by a tapering off in September with 202 mm (7.9 in). By autumn, precipitation decreases significantly, with October and November receiving 124 mm (4.9 in) and 77 mm (3.0 in), respectively, as the region prepares for the drier winter season.
In Kumamoto, Japan, sunshine duration exhibits a clear seasonal progression, with a steady increase from the depths of winter into the vibrant summer months. January sees the lowest sunlight exposure, at 184 hours, gradually climbing as the days lengthen. By February, sunshine hours rise to 235, and this upward trend continues into March with 264 hours, setting the stage for the more sun-drenched late spring. April and May both achieve 281 hours, reflecting the region's transition into a temperate climate characterized by pleasant, sunny days that create ideal conditions for outdoor activities.
Summer in Kumamoto truly shines, with August emerging as the peak month, boasting 298 hours of sunlight. This abundance of sunshine enhances the warm weather, allowing residents to fully enjoy the season's outdoor attractions. Even as the summer wanes, sunlight remains plentiful, with September and October maintaining 255 hours each. However, by November and December, the trend shifts slightly, as daylight hours decrease to 236 and 221 hours, respectively, heralding the arrival of winter. This seasonal pattern underscores Kumamoto's inviting climate, with a distinct pattern of increasing sunlight culminating in the vibrant summer months.
In Kumamoto, Japan, the UV Index demonstrates a pronounced seasonal variation, peaking during the summer months and decreasing significantly in winter. Starting in January, the UV Index is relatively moderate at 5, leading to a burn time of 30 minutes. As spring approaches, the UV levels begin to rise, with February increasing to 6 (high exposure) and March reaching a notably intense 9, categorized as very high, which reduces recommended burn time to just 15 minutes. This upward trajectory continues in April, where the index hits 11 (extreme), and both May and June maintain this intensity, indicating the critical need for skin protection during these months.
The summer months of July and August hold the highest UV Index readings, peaking at 13 (extreme), with an urgent burn time of just 10 minutes. As autumn approaches, UV levels begin to recede, with September dropping to 11, followed by October at 8, representing very high exposure levels. November and December bring a return to moderate UV conditions, with indices of 6 and 4, respectively, allowing for longer exposure times of 25 to 30 minutes without significant risk of skin damage. This seasonal analysis highlights the importance of sun safety measures, particularly during the intense summer months when UV radiation poses the greatest threat.
UV Risk Categories
In Kumamoto, Japan, daylight duration exhibits a clear seasonal pattern, steadily increasing from winter to summer and then gradually declining towards winter again. Both January and February provide a modest 10 hours of daylight, characteristic of the colder months. As spring unfolds in March, daylight extends to 11 hours, which encourages outdoor activities and the reawakening of nature. The trend continues to rise in April and May, reaching 12 and 13 hours, respectively, allowing for increasingly longer evenings to enjoy as temperatures warm.
Summer in Kumamoto sees daylight at its peak, with June and July boasting 14 hours of sunlight, offering ample opportunities for outdoor enjoyment during the warmest months. As August arrives, daylight begins to wane slightly but remains respectable at 13 hours. The descent continues in autumn, with daylight hours tapering to 12 in September and back down to 10 by November. This cyclical pattern reflects the balance of sunlight throughout the year, emphasizing the region's seasonal transformations and the opportunities for outdoor activities that accompany the longer days of summer.
Amakusa, Japan experiences a humid climate with significant temperature variations throughout the year. Winter months are relatively mild, with January temperatures ranging from -2°C to 21°C, while summers can be hot and humid, particularly in July and August, with maximum temperatures reaching 39°C. Precipitation peaks in July at 475 mm, contributing to wet conditions during the rainy season. Despite the high rainfall, the region enjoys considerable sunshine, especially in August, which sees around 305 hours of sun. For more detailed information, visit Amakusa climate.
The climate in Aso, Japan, features distinct seasonal variations, with the coldest months being January and February, where temperatures can drop to -8°C (18°F) and rise to a maximum of 19°C (67°F). The warmest months, July and August, see minimum temperatures of around 16°C (62°F) and peak at 35°C (96°F). Aso experiences significant rainfall, particularly in July, which averages 452 mm (17.8 in), while sunshine hours are ample in summer with August reaching 294 hours. Overall, the region showcases a dynamic climate that includes cold winters, warm summers, and abundant precipitation. For more detailed information, visit Aso climate.
Kamiamakusa, Japan, experiences a diverse climate with distinct seasonal changes. Winters are cool, with temperatures ranging from -2°C (29°F) in January to around 7°C (46°F) on average. Summers can be hot and humid, especially in July and August, with average temperatures peaking at 29°C (84°F) and 36°C (96°F) respectively. Precipitation is significant during the summer months, with July receiving the highest at 427 mm (16.8 in), while sunshine hours are plentiful in August, totaling 305 hours. For more detailed information, visit Kamiamakusa climate.
Koshi, Japan experiences a temperate climate with distinct seasonal variations. Winter months (December to February) are cold, with January averaging around 6°C (42°F) and experiencing significant snowfall. As spring approaches, temperatures rise dramatically, peaking in July and August at an average of 26°C (79°F) and 28°C (82°F), respectively, accompanied by high precipitation, especially in July with 478 mm (18.8 in) of rainfall. The region boasts abundant sunshine, particularly in August, which enjoys up to 294 hours of sunlight. For more detailed information about the climate, visit Koshi climate.
Kumamoto, Japan experiences a temperate climate characterized by distinct seasons. Winters (January to February) are cool, with average temperatures ranging from 6°C to 7°C and moderate precipitation, while summers (July to August) are hot and humid, reaching average temperatures of 26°C to 27°C and significant rainfall, particularly in July with 406 mm. The city enjoys ample sunshine, especially in August with 294 hours, making it one of the sunniest months. Overall, Kumamoto presents a mix of pleasant weather and seasonal variations throughout the year. For more detailed information, visit Kumamoto climate.
Minamata, Japan experiences a temperate climate characterized by distinct seasons. Winters (January and February) are cold, with average temperatures around 7-8°C (44-46°F), while summers (July and August) can be quite hot, averaging 27-28°C (80-82°F) and reaching maximums of 35°C (96°F). Precipitation is abundant, particularly from June to August, with July receiving the highest rainfall at 465 mm (18.3 in). Sunshine is plentiful in the summer months, peaking in August with 305 hours, contributing to a vibrant local ecosystem. For more detailed information, visit Minamata climate.
In conclusion, Kumamoto, Japan, showcases a dynamic climate characterized by distinct variations in temperature, precipitation, sunshine duration, UV Index, and daylight hours across the seasons. The humid subtropical climate offers a broad range of temperatures, from the chilly depths of winter to the sweltering heat of summer, while its rainfall patterns emphasize significant moisture during the warmer months. Sunlight peaks dramatically in July and August, coinciding with the highest UV exposures, urging residents and visitors to protect their skin while enjoying the outdoors. This interplay of climatic factors not only influences daily life in Kumamoto but also enhances the region's vibrant natural beauty—making it an ideal destination for those seeking to explore diverse seasonal experiences.