Last updated: January 18, 2025
Hiroshima, Japan, exhibits a Cfa designation according to the Köppen-Geiger climate classification, characterizing it as a humid subtropical climate. This region experiences a remarkable temperature range, with winter lows plunging to a minimum of -15°C (5°F) in February and summer highs soaring to a maximum of 38°C (101°F) in August. The annual average temperature hovers around 16°C (61°F), reflecting the city's diverse climatic conditions and providing a unique backdrop for its rich cultural heritage and vibrant natural landscape.
Hiroshima, Japan, experiences distinct seasonal temperature patterns characterized by cold winters and hot summers. In the winter months of January and February, temperatures can dip as low as -15°C (5°F), with average highs hovering around 6°C (42°F), creating a chilly atmosphere. As spring arrives in March and April, temperatures gradually rise, reaching average highs of 26°C (80°F) by late April, marking a transition to more comfortable conditions. The warmth continues into summer, peaking in July and August, where average temperatures soar to 28°C (82°F) and 38°C (101°F), respectively. In September, a slight cooling occurs, but temperatures remain warm through October, before the onset of cooler autumn months, where averages drop to 13°C (55°F) in November. This seasonal progression highlights Hiroshima's climatic versatility, with a blend of cold winters, mild springs, hot summers, and pleasantly cool autumns.
The climate in the Hiroshima region exhibits a range of temperatures throughout the year. In Miyajima, the temperatures vary from a minimum of -4°C (25°F) in January to a maximum of 35°C (96°F) in August, as detailed here. Onomichi experiences slightly colder temperatures, with a minimum of -5°C (24°F) in January and reaching up to 38°C (100°F) in July, which can be checked here. Meanwhile, Hiroshima itself sees the coldest temperature of -7°C (19°F) in February, while peaking at 36°C (97°F) in August, more information can be found here.
Hiroshima, Japan, experiences a significant variation in monthly precipitation, with a pronounced wet season coinciding with the summer months. January and February witness lower precipitation levels, with January receiving 49 mm (1.9 in) and February slightly more at 64 mm (2.5 in). As spring unfolds in March, rainfall increases substantially, peaking at 112 mm (4.4 in). The trend continues into April and May, where precipitation averages around 127 mm (5.0 in) and 122 mm (4.8 in), respectively, contributing to the lush greenery characteristic of the region during this period.
The summer months, particularly July, bring the highest levels of rainfall, with 351 mm (13.8 in) noted—a pivotal month in Hiroshima's climate due to the increased risk of heavy downpours. August and September also retain substantial rainfall, with 211 mm (8.3 in) and 206 mm (8.1 in), respectively. As fall approaches, October sees a decrease to 171 mm (6.7 in), followed by a sharp decline in November to 38 mm (1.5 in). The winter months of December and January close the year with modest rains, amounting to 59 mm (2.3 in) and 49 mm (1.9 in), highlighting the seasonal shift in precipitation patterns throughout the year.
Hiroshima, Japan, exhibits a clear seasonal pattern in sunshine duration, characterized by a steady increase from winter to summer. January receives a modest 182 hours of sunshine, which gradually climbs through February and March to reach 266 hours as spring approaches. The upward trend continues in April, with sunshine peaking at 283 hours during this transitional month, setting the stage for the lush and vibrant conditions typical of late spring and early summer.
The summer months of June, July, and August showcase the region's sunniest period, with August standing out as the pinnacle of sunshine, boasting 308 hours. This warmth and brightness are crucial for agriculture and the outdoor lifestyle that citizens enjoy. However, as summer wanes into September and October, there is a noticeable decrease in sunshine hours, dropping to 260 hours and 252 hours, respectively. The year concludes with shorter days in November and December, where sunshine hours decrease to 237 and 218 hours, continuing the trend of winter's diminished light. Overall, Hiroshima's sunshine variability reflects the broader seasonal changes, significantly influencing the local climate and daily life.
The UV Index in Hiroshima, Japan, reveals significant seasonal variations, particularly as the year transitions from winter to summer. In winter months like January and December, the UV Index remains relatively low at 4, indicating a moderate exposure level with a recommended burn time of 30 minutes. However, as spring approaches, the UV levels rise sharply, reaching 6 in February and hitting 8 in March, classified as high and very high, respectively. This progression highlights the importance of increased sun protection as temperatures begin to warm.
The summer months present the most intense UV conditions, with the Index soaring to 12 in both July and August—characterized as extreme with a burn time of only 10 minutes. This high level of UV radiation underscores the necessity for effective sun safety measures during the hot season. As fall approaches, the UV Index begins to decline, falling to 10 in September and then gradually decreasing to 6 in November before returning to the moderate level of 4 in December. The fluctuating UV levels throughout the year serve as a reminder of the changing sun exposure risks in Hiroshima's climate, necessitating vigilance, particularly during the peak summer months.
UV Risk Categories
Daylight duration in Hiroshima, Japan, showcases a dynamic pattern that reflects the changing seasons. In the depths of winter, January and February provide relatively consistent daylight, with each month offering about 10 hours. As March arrives, the days begin to lengthen, reaching 11 hours, signaling the transition towards spring. April and May further enhance this trend, with daylight extending to 13 hours as nature awakens and blossoms, offering ample light for outdoor activities.
The peak daylight duration occurs during the summer months of June and July, where residents can enjoy up to 14 hours of sunlight, creating bright and extended days. As August rolls in, daylight starts to taper off slightly to 13 hours, followed by a gradual decline through September and October, where daylight durations return to 12 and 11 hours, respectively. By November, daylight decreases again to 10 hours, and winter sets in with December featuring the shortest day of the year at 9 hours. This cyclical ebb and flow of daylight profoundly influences both the local climate and the lifestyle of Hiroshima's inhabitants.
Hatsukaichi, Japan, experiences a temperate climate with distinct seasonal variations. Winters (December to February) are cold with temperatures ranging from -4°C to 15°C, while summers (June to August) are hot, peaking at 35°C. Rainfall is abundant, particularly in July, which records an average of 386 mm of precipitation, the highest month. Sunshine hours are plentiful, especially in August, with about 308 hours of sunshine. For more detailed information, visit Hatsukaichi climate.
Hiroshima, Japan experiences a humid subtropical climate with four distinct seasons. Winters are cold, with January averages around 4°C (39°F) and temperatures ranging from -7°C (20°F) to 14°C (58°F). Summers are hot and humid, particularly in July and August, where average temperatures reach 26°C (78°F) and 27°C (81°F) respectively, accompanied by heavy rainfall, especially in July with 391 mm (15.4 in) of precipitation. Sunshine hours peak in August with 308 hours, providing ample sunlight during the warmer months. For more detailed information, visit Hiroshima climate.
Miyajima, Japan experiences a diverse climate throughout the year, with winter temperatures ranging from -4°C in January to 15°C in December. The spring months (March to May) see average temperatures rise from 10°C to 19°C, while summer months (June to August) can reach a maximum of 35°C. Precipitation is abundant, especially in July with 386 mm, making it the wettest month. Despite the rainfall, Miyajima enjoys considerable sunshine, peaking in August with 308 hours. For more detailed information, visit Miyajima climate.
Onomichi, Japan experiences a diverse climate characterized by distinct seasonal variations. Winters are cool, with January temperatures averaging around 6°C (43°F), while summers can be hot and humid, peaking in July with an average of 27°C (81°F). Precipitation is highest in July at 314 mm (12.4 in), contributing to a wetter season, while May sees significant sunshine with about 305 hours. The city enjoys a relatively mild climate overall, with average temperatures ranging from 6°C (43°F) in winter to 29°C (85°F) in summer. For more detailed information, visit Onomichi climate.
In conclusion, Hiroshima, Japan, exemplifies a region where climate factors, such as temperature, precipitation, UV index, and daylight duration, interact to create a unique environmental experience. The city experiences a distinct range of temperatures that fluctuate with the seasons, characterized by cold winters and hot, humid summers. Precipitation patterns reveal a marked increase during the summer months, aligning with the peak in sunshine and UV intensity that necessitates caution and protective measures against sun exposure. Meanwhile, the varying daylight duration throughout the year not only impacts the daily rhythm of life in Hiroshima but also enhances the region's agricultural productivity and cultural festivities. Overall, understanding these climatic dynamics is essential for residents and visitors alike, guiding them in adapting to the varied seasonal influences that define Hiroshima's vibrant atmosphere.