Last updated: January 18, 2025
The climate of Ibaraki, Japan, classified under the Köppen-Geiger system as Cfa, is characterized by a humid subtropical climate with significant seasonal variations. Winters can be quite cold, with minimum temperatures dropping to -11°C (12°F) in January, while summers experience a remarkable shift with average temperatures reaching 16°C (60°F) and soaring to a maximum of 38°C (102°F) in July. This dynamic temperature range not only shapes the region's weather patterns but also influences local ecosystems and agricultural practices, making it a unique area for climate studies.
Ibaraki, Japan experiences marked seasonal temperature variations throughout the year, beginning with the cold winter months of January and February, where temperatures can plummet to -11°C (12°F) and -6°C (22°F) respectively. As spring progresses into March and April, there is a gradual warming trend, with average temperatures rising to 10°C (50°F) in March and reaching 14°C (57°F) in April, alongside increasing maximum temperatures that peak at 29°C (85°F). The transition into summer brings much warmer conditions, with July and August seeing average temperatures soar to 25°C (78°F) and 27°C (81°F), with maximums frequently hitting 38°C (102°F). Autumn introduces a cooling trend, with temperatures gradually falling back to averages of 18°C (65°F) in October, further retreating to 13°C (55°F) by November. The cycle concludes with a return to winter conditions in December, where temperatures once again drop, highlighting the region's distinct seasonal dynamics.
Oarai and Mito share similar temperature ranges, experiencing a minimum of -3°C (27°F) in January and a maximum of 33°C (92°F) in August, as detailed in their respective monthly temperature links: monthly temperatures in Oarai and monthly temperatures in Mito. In contrast, Tsukuba experiences colder winter temperatures, with a minimum of -10°C (14°F) in January, while enjoying hotter summers, peaking at 37°C (98°F) in August, as outlined in the monthly temperatures in Tsukuba.
Ibaraki, Japan experiences a varied precipitation pattern throughout the year, with rainfall peaking during the warmer months. The winter months of January and February see relatively low levels of precipitation, at 46 mm (1.8 in) and 42 mm (1.7 in) respectively, occurring over a modest number of rain days (5 and 7 days). As spring arrives, precipitation begins to increase significantly, particularly in March and April, where rainfall reaches 136 mm (5.3 in) and 118 mm (4.7 in), accompanied by 11 rain days each. May continues this trend with 130 mm (5.1 in) of rainfall as the region transitions fully into the wetter summer months.
The peak of precipitation occurs in July, with a substantial 217 mm (8.5 in) accumulated over 19 rain days, marking the height of the rainy season. This is followed by a slight decrease in August to 119 mm (4.7 in) across 13 rainy days. The precipitation remains considerable into autumn, especially in October, where 241 mm (9.5 in) falls over 14 days. November and December see a reduction in both rainfall and the number of rainy days, with 81 mm (3.2 in) and 61 mm (2.4 in) respectively, concluding the year with drier conditions. This seasonal variability highlights the dynamic weather patterns characteristic of the region.
In Ibaraki, Japan, sunshine duration exhibits a distinct seasonal trend, starting with relatively shorter daylight hours in winter. January records 188 hours of sunshine, which gradually increases to 235 hours in February as the region begins to warm. This upward trajectory continues through the spring months, culminating in April and May, where daily sunshine hours peak, achieving 277 hours and 283 hours, respectively. This period of increased sunlight not only enhances the vibrancy of the landscape but also supports agricultural productivity as the region transitions into the warmer months.
As summer approaches, August notably stands out as the month with the highest recorded sunshine, accruing an impressive 285 hours. While sunshine hours begin to decline in September to 237 hours, the overall summer remains bright, with July also contributing 245 hours. By autumn, the sunshine hours maintain a decent level, with October having 211 hours and November slightly rebounding to 231 hours. This overall pattern emphasizes the favorable conditions during the spring and summer months, making Ibaraki a region with notable seasonal variations in sunshine that significantly impact both the local climate and lifestyle.
The UV Index in Ibaraki, Japan exhibits significant variations throughout the year, reflecting seasonal changes in sun exposure. In winter, both January and December present a moderate UV Index of 3, with a corresponding burn time of 30 minutes. February sees a slight increase to a UV Index of 5, indicating a moderate exposure category that still requires some sun protection. As spring emerges, the UV Index escalates sharply in March, reaching 8 and remaining in the very high exposure category through April. This upward trend culminates in May, where the UV Index peaks at 11, categorizing it as extreme and reducing the safe exposure time to just 10 minutes.
The summer months maintain this extreme UV Index level, with 11 recorded from June through August, emphasizing the importance of sun safety during this period. As autumn arrives, there is a gradual decline; September witnesses a drop to 9, remaining in the very high category, while October registers a UV Index of 7, classified as high, with a burn time extending to 25 minutes. The UV Index again moderates in November and December, highlighting Ibaraki’s distinct seasonal patterns in sun exposure, which necessitate careful attention to sun protection strategies, especially during the spring and summer months when UV levels are at their highest.
UV Risk Categories
In Ibaraki, Japan, daylight duration exhibits a clear seasonal progression, beginning with shorter daylight hours in the winter months. January and December each offer about 9 hours of sunlight, while February sees a slight increase to 10 hours. This gradual extension of daylight continues through March, where the duration reaches 11 hours. The arrival of spring leads to a noticeable increase, with daylight peaking at 14 hours in both May and June, creating longer evenings that encourage outdoor activities and bolster the region's vibrant spring and summer atmosphere.
As summer transitions to autumn, daylight begins to taper off, with July and August maintaining 14 hours before descending to 13 hours in September. October further decreases the daylight to 11 hours, while November drops to 10 hours as the region heads back into winter. This cyclical pattern not only reflects the natural changes of the seasons but also influences daily life in Ibaraki, as residents adapt their activities to the varying lengths of daylight throughout the year.
Mito, Japan experiences a temperate climate, with cold winters and warm summers. January temperatures range from -3°C to a mild 15°C, while July sees warmer averages between 19°C and 31°C. Precipitation peaks in June and October, with July recording the highest rainfall at 209 mm. Sunshine is prevalent throughout the year, especially in August with 288 hours. For more detailed information, visit Mito climate.
Oarai, Japan experiences a temperate climate with distinct seasonal variations. Winters (December to February) are cool, with average temperatures ranging from 6°C (43°F) to 8°C (47°F) and moderate precipitation, peaking in March. Summers (June to August) are warm and humid, featuring average highs between 24°C (76°F) and 26°C (80°F) and the highest rainfall in July. The area enjoys a good amount of sunshine, particularly in August, with 288 hours of sun. For more details, visit the Oarai climate page.
Tsukuba, Japan experiences a varied climate throughout the year, with winter temperatures ranging from -10°C (14°F) in January to a maximum of 29°C (84°F) in April. Summers can be quite hot, with average highs reaching up to 37°C (98°F) in July and August. Precipitation is significant, particularly in July and October, with monthly averages exceeding 200 mm (7.9 in). Despite this, the city enjoys ample sunshine, particularly in the spring and early summer, with May recording an impressive 274 hours. For more detailed information, visit Tsukuba climate.
In conclusion, Ibaraki, Japan, showcases a diverse climate characterized by distinct seasonal variations in temperature, precipitation, sunshine duration, UV Index, and daylight hours. The transition from cold winters to warm summers significantly influences the region's weather patterns, contributing to vibrant spring blooms and active summer days. Notably, the extreme UV Index during the summer months necessitates vigilant sun protection, while the fluctuating daylight duration encourages residents to embrace outdoor activities. As Ibaraki experiences these dynamic changes throughout the year, understanding its climatic trends is essential for both locals and visitors alike, highlighting the beauty and complexity of this unique Japanese region.