Last updated: January 18, 2025
The climate of Ehime, Japan, is characterized by a Köppen-Geiger classification of Cfa, indicating a humid subtropical climate with distinct seasonal variations. Winter temperatures can plunge to a minimum of -10°C (15°F) in February, while the summer months bring an average high of 37°C (99°F) in August. The region enjoys a comfortable annual mean temperature of 16°C (61°F), highlighting the striking contrasts between its cold winters and hot, humid summers. Such climatic conditions foster a unique ecosystem and significantly influence local agricultural practices.
In Ehime, Japan, temperature patterns exhibit a pronounced seasonal cycle, beginning with the coldest months of January and February, where minimum temperatures can dip to -10°C (15°F), coupled with average highs reaching only the low twenties. As winter transitions into spring, temperatures gradually rise, with March witnessing a significant increase in warmth, highlighted by a rise in average temperatures to 10°C (50°F) and maximums of 23°C (74°F) by the month's end. April and May continue this upward trend, showcasing more pleasant spring conditions with averages nearing 18°C (66°F) and maximums exceeding 30°C (86°F). The onset of summer in June brings high humidity and average maximums reaching the upper twenties, peaking in August, when the heat reaches its zenith at 37°C (99°F). Following the sweltering summer, temperatures begin to decline in September, gradually shifting towards cooler fall conditions in October and November, with lows dipping again toward freezing in December. This fluctuation between warm summers and cold winters underpins the distinctive climate of Ehime.
Matsuyama experiences a minimum temperature of -4°C (24°F) in February and a maximum of 33°C (91°F) in August, while Uwajima records slightly milder temperatures with a minimum of -2°C (28°F) in February and a maximum of 36°C (97°F) in August. In Imabari-shi, temperatures vary from a minimum of -3°C (27°F) in January to a maximum of 32°C (89°F) in August. For more detailed information, visit the monthly temperatures in Matsuyama, Uwajima, and Imabari-shi.
Precipitation in Ehime, Japan, exhibits notable seasonal variation, peaking during the summer months. January begins the year with relatively low rainfall at 60 mm (2.4 in), but as temperatures rise towards February and March, precipitation increases significantly, reaching 132 mm (5.2 in) in March. This trend continues into spring, with April and May recording rainfall amounts of 138 mm (5.4 in) and 158 mm (6.2 in), respectively, setting the stage for the humid conditions of summer. The rainy season culminates in July, where precipitation soars to 373 mm (14.7 in), marking the wettest month of the year.
Following July, rainfall begins to decrease but remains substantial in August and September, with totals of 194 mm (7.6 in) and 221 mm (8.7 in). October sees a slight increase to 223 mm (8.8 in), showcasing a transition from summer to autumn. Towards the year's end, November and December drop back down to 63 mm (2.5 in) and 71 mm (2.8 in), respectively, leading to drier conditions and fewer rainy days. This precipitation pattern reveals a typical monsoonal influence, with intense rain primarily concentrated in the summer months and more moderate levels during winter.
In Ehime, Japan, sunshine duration exhibits a distinct seasonal pattern, showcasing a steady increase from winter into summer. The year begins with 189 hours of sunshine in January, gradually climbing to 235 hours in February and reaching 272 hours in March. This upward trend accelerates during the spring, with April and May basking in 287 hours and 303 hours, respectively, as longer days and clearer skies herald the approach of summer. This rise continues into the summer months, peaking in August, where radiant sunshine totals an impressive 312 hours—the highest for the year.
As summer transitions to fall, sunshine hours begin to taper off, though September still retains a commendable 266 hours. Moving into October and November, the decline continues with 258 hours and 242 hours, respectively, reflecting shorter days and increased cloud cover as winter approaches. Lastly, December rounds out the year with 225 hours of sunshine, indicating a lingering but reduced exposure to sunlight. This seasonal cycle of sunshine not only characterizes the climate of Ehime but also underscores the region’s vibrant summer, where the abundance of sunny days fosters a rich and lively atmosphere.
The UV Index in Ehime, Japan, demonstrates significant seasonal fluctuations, reflecting the region's shifting exposure to ultraviolet radiation throughout the year. Starting with a moderate UV Index of 4 in January, the intensity of sun exposure increases as spring approaches, reaching 6 in February and jumping to 9 by March. This marks the beginning of a critical period, as April brings an extreme UV Index of 11, and May continues this trend at 12, indicating that sun safety becomes paramount due to rapidly decreasing burn times of just 10 minutes during these months.
As summer peaks, the UV Index in Ehime remains at its highest, consistently at 12 from June through August, necessitating vigilant sun protection for outdoor activities. The intensity begins to wane in September with a slight decrease to 11, followed by an 8 in October, signifying gradually improving conditions. November and December see a return to 6 and 4, respectively, both classified as high and moderate, allowing residents to enjoy the outdoors without immediate sun-related risks. This cyclical pattern of UV exposure underscores the importance of understanding seasonal variations for effective sun safety practices throughout the year.
UV Risk Categories
In Ehime, Japan, daylight duration follows a clear seasonal pattern, reflecting the changing lengths of days throughout the year. Starting in January and February, residents enjoy approximately 10 hours of daylight, gradually increasing to 11 hours by March as spring approaches. This upward trend continues into April and May, where daylight reaches 13 hours, providing longer afternoons and more opportunities for outdoor activities. By June and July, the duration reaches its peak at 14 hours, offering the longest days of the year, ideal for enjoying the vibrant summer landscape.
As summer transitions into fall, daylight duration begins to decline. In August, it retreats to 13 hours, before further decreasing to 12 hours in September. The decline continues into October and November, with daylight waning to 11 hours and 10 hours, respectively, as the days grow shorter. By December, daylight is at its shortest with only 9 hours of light. This annual daylight cycle not only influences the daily rhythms of life in Ehime but also shapes the cultural and agricultural practices that celebrate the changing seasons.
Imabari-shi experiences a temperate climate with distinct seasons. Winters are cool, with January temperatures averaging around 6°C (42°F) and significant precipitation peaking in July at 360 mm (14.2 in). Summers are warm and humid, particularly in August when average temperatures reach 27°C (81°F) and sunshine hours are the highest, totaling 313. Rainfall is notable from April to June, contributing to lush greenery. For more detailed information, visit Imabari-shi climate.
Matsuyama, Japan experiences a temperate climate with four distinct seasons. Winter temperatures range from -4°C (25°F) to 15°C (59°F), while summers are warm, with averages reaching up to 26°C (79°F) in July. The region receives significant rainfall, particularly in July (374 mm), marking it as the wettest month. Sunshine hours peak in August, totaling 313 hours, offering a vibrant summer. For more information, visit Matsuyama climate.
Uwajima, Japan, experiences a temperate climate with distinct seasonal variations. Winters are mild, with average temperatures ranging from 7°C (45°F) in January to around 9°C (49°F) in December, while summers can be hot and humid, peaking in July and August with average temperatures of 27°C (80°F) and 28°C (83°F), respectively. Precipitation is abundant, particularly in July when it reaches 353 mm (13.9 in). Sunshine hours vary, peaking in August with 308 hours, contributing to the region's lush greenery. For more details, visit Uwajima climate.
In conclusion, the climate and environmental patterns of Ehime, Japan, reveal a dynamic interplay between temperature, precipitation, sunshine duration, UV Index, and daylight hours. With its humid subtropical climate, Ehime experiences distinct seasonal shifts, from the frigid minimums of winter to the sweltering heat of summer. The region's significant rainfall during the summer months, coupled with peak sunshine and high UV Index levels, underscores the importance of effective sun protection and awareness of weather conditions. Additionally, the variation in daylight duration throughout the year not only enriches the local natural beauty but also influences cultural and agricultural activities. By understanding these climatic characteristics, residents and visitors alike can better appreciate the nuances of Ehime's environment and engage in practices that align with its seasonal rhythms.