Last updated: January 18, 2025
Yamaguchi, Japan, is characterized by a Cfa Köppen-Geiger climate, indicating a humid subtropical environment. The region experiences a wide temperature range, with minimums dipping to -4°C (25°F) in January, reflecting the coldest part of the year. Conversely, average temperatures hover around 17°C (62°F), providing a temperate climate throughout most seasons. In August, the heat peaks, with maximum temperatures soaring to 38°C (100°F), emphasizing the region's warm summers. This diversity in temperature underscores Yamaguchi's unique climatic conditions, influencing both its natural landscapes and human activities.
Yamaguchi, Japan, experiences distinct seasonal temperature patterns that reflect its humid subtropical climate. Winter months, particularly January and February, are characterized by colder temperatures, with minimums plummeting to -4°C (25°F) and average highs around 17°C (64°F). As spring unfolds in March and April, temperatures gradually rise, with averages climbing from 11°C (51°F) to 14°C (58°F) and maximums reaching up to 27°C (80°F). The onset of summer in May brings warmer weather, peaking in July and August, where daily averages soar to around 28°C (82°F) and maximums can touch 38°C (100°F). As autumn arrives in September, temperatures begin to cool, with averages of 24°C (76°F) and minimums around 13°C (56°F), before settling back to cooler conditions by November and December. This fluctuation showcases the region's diverse climate, influencing both its ecology and lifestyle throughout the year.
Shimonoseki experiences a minimum temperature of -1°C (30°F) in January and a maximum of 32°C (89°F) in August, presenting a moderate climate overall. In contrast, Yamaguchi records a colder minimum of -4°C (25°F) in January and a higher maximum of 38°C (100°F) in August, indicating a wider temperature range. Similarly, Iwakuni shares the same January minimum of -4°C (25°F) but has a slightly lower August maximum of 35°C (96°F), making its summer less extreme than Yamaguchi. For detailed monthly temperatures, see Shimonoseki's monthly temperatures in Shimonoseki, Yamaguchi's monthly temperatures in Yamaguchi, and Iwakuni's monthly temperatures in Iwakuni.
Yamaguchi, Japan, demonstrates a varied precipitation pattern throughout the year, with distinct wet and dry periods that align closely with seasonal transitions. January and February are relatively drier months, with precipitation measuring 62 mm (2.4 in) and 82 mm (3.2 in), respectively, and typically seeing around 9 days of rainfall each. As spring approaches, rainfall begins to intensify, peaking in May with 148 mm (5.8 in) over approximately 9 rainy days. June marks the onset of the summer rainy season, with precipitation escalating dramatically to 196 mm (7.7 in) across 12 days, setting the stage for the heaviest rainfall of the year.
The peak of the wet season occurs in July, where Yamaguchi experiences a significant spike in precipitation, accumulating a substantial 330 mm (13.0 in) over 18 days, making it the rainiest month. Following July, August and September also see considerable rainfall, with averages of 243 mm (9.6 in) and 224 mm (8.8 in), respectively. The autumn months bring a gradual decrease in precipitation, dropping to 137 mm (5.4 in) in October and further down to 45 mm (1.8 in) in November. Despite December experiencing mild precipitation at 70 mm (2.8 in), the overall trend indicates a clear seasonal shift, establishing Yamaguchi's climate as notably influenced by its distinct wet and dry periods throughout the year.
In Yamaguchi, Japan, the duration of sunshine showcases a clear seasonal pattern, with a notable increase as the year progresses from winter to summer. January begins the year with a modest 175 hours of sunshine, gradually rising to 229 hours in February. This upward trend continues, culminating in spring with March and April enjoying 264 hours and 279 hours respectively. By May, as the days grow longer and warmer, sunshine duration reaches 299 hours, marking a significant turning point as Yamaguchi transitions into the summer months.
The peak of sunshine occurs in August, where residents bask in an impressive 303 hours of sunlight, making it the sunniest month of the year. Following the summer peak, sunshine hours begin to decline, settling back to 276 hours in July and 255 hours in both September and October as fall approaches. The decline continues into November with 234 hours and eventually to 212 hours in December, indicating a return to more overcast conditions. This cyclical pattern of sunshine hours reflects the broader shifts in climate throughout the year, showcasing Yamaguchi's warmest days as vibrant and sunlit, while the winter months are more subdued in light.
The UV Index in Yamaguchi, Japan, exhibits notable seasonal variations, reflecting the changing intensity of sunlight throughout the year. Beginning in winter, January and February register a moderate UV Index of 4 and 5, respectively, with recommended burn times of 30 minutes for unprotected skin. As spring emerges, the UV Index escalates significantly, reaching 8 in March and soaring to 11 during both April and May. This shift indicates a transition to very high and extreme UV levels, where the recommended burn time decreases to just 10 minutes, highlighting the increased need for sun protection as warmer weather approaches.
The summer months see the UV Index peak, with both July and August reaching an extreme level of 12, emphasizing the critical importance of protective measures against sun exposure during these months. As autumn sets in, the UV levels taper off, with September recording a UV Index of 10 and a burn time of 15 minutes, followed by 7 in October and 6 in November, categorizing them as high exposure. By December, the UV Index declines back to 4, similar to the early months of the year. This cyclical pattern underscores the importance of adjusting sun protection measures according to the UV Index, particularly during the intense summer months when risks are at their highest.
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In Yamaguchi, Japan, daylight duration experiences a clear seasonal rhythm, evolving from the shorter days of winter to the longer days of summer. January and February both see 10 hours of daylight, providing a steady but limited amount of natural light. As spring arrives in March, this duration increases slightly to 11 hours, marking the beginning of longer days. By April and May, daylight extends to 13 hours, allowing residents to fully embrace the rejuvenating energy of spring.
As summer sets in, daylight reaches its peak in June and July, with the longest durations of 14 hours. This extended exposure fosters an environment ripe for outdoor activities and growth. However, as summer transitions into autumn, daylight hours gradually diminish, decreasing to 13 hours in August and 12 hours in September. By October, the duration further contracts to 11 hours, followed by 10 hours in November and a reduced 9 hours in December, signaling the return to the shorter winter days. This cyclical pattern of daylight duration highlights the interplay between seasonal changes and daily life in Yamaguchi.
Iwakuni, Japan experiences a wide range of temperatures throughout the year, with January averaging 5°C (42°F) and peaking at 35°C (95°F) in July and August. The region sees significant rainfall, particularly in July with 386 mm (15.2 in) and relatively lower precipitation in November at 37 mm (1.5 in). Sunshine is abundant, especially in May and August, which record over 300 hours of sunlight. For more details on the climate, visit Iwakuni climate.
Shimonoseki, Japan experiences a temperate climate with distinct seasonal variations. Winter months, particularly January and February, are chilly with average temperatures around 8°C (46°F) and significant precipitation peaking in March at 165 mm (6.5 in). Summers are warm and humid, with July and August averaging 25-27°C (78-81°F) and high rainfall, especially in July at 295 mm (11.6 in). Sunshine is abundant in summer, exceeding 300 hours in August, while winter sees around 178 hours of sunlight in January. For more details, visit Shimonoseki climate.
Yamaguchi, Japan experiences a humid subtropical climate with distinct seasonal variations. Winter months, particularly January and February, showcase chillier temperatures ranging from -4°C to a maximum of 22°C while recording significant precipitation, peaking in March and June. Summer months are warm to hot, with averages reaching up to 28°C in August, accompanied by substantial rainfall, particularly in July. The region is relatively sunny, with the most sunshine hours occurring in May and August. For more details, visit Yamaguchi climate.
In conclusion, the climate of Yamaguchi, Japan, is marked by its distinct seasonal variations in temperature, precipitation, sunshine duration, UV Index, and daylight. The region experiences cold winters that transition into warm, humid summers, characterized by significant rainfall and extended daylight hours. Understanding these climatic patterns not only enriches the appreciation of Yamaguchi’s natural environment but also underscores the importance of adapting to changing weather conditions throughout the year. Whether enjoying the vibrant sunlight of summer or preparing for the cooler, overcast winters, residents and visitors alike can engage meaningfully with the rhythms of Yamaguchi's climate, fostering a deeper connection to this unique locale.