Weather Changes and Seasonal Climate Characteristics of the Japanese Archipelago

The Japanese archipelago is situated in a long, east-west direction, resulting in diverse climates across different regions. However, it generally falls within the temperate monsoon climate zone. Throughout the year, migratory high-pressure and low-pressure systems pass through, leading to various weather phenomena in each season.

As spring arrives, cold fronts traverse the Japanese archipelago, bringing frequent blustery days with rain and wind. In the Okinawa region, this period is known as 'Ninguchi Kajimari (February windy days)', where sudden changes in atmospheric pressure can trigger strong winds and heavy rain.

In early May, the Japanese archipelago officially enters the 梅雨 (Tsuyu/Rainy Season) period. Okinawa experiences the start of the rainy season around May 10th, while the mainland regions enter the influence of the rainy season front in early June. The stationary front's activity leads to prolonged rainfall, and occasionally, torrential downpours.

By late June, the influence of the northward-moving Okhotsk Sea high-pressure system brings an end to the rainy season in the mainland regions, ushering in the true summer weather. However, in Okinawa, the period after the rainy season sees the prevalence of strong southwest monsoons, known as 'Kachibe (summer southerly winds).'

August sees a significant impact from typhoons, tropical cyclones that form along the periphery of the North Pacific High. Okinawa, in particular, experiences the most typhoon activity throughout the year. This can lead to frequent strong winds and heavy rainfall, sometimes causing damage to crops.

As autumn arrives, the Japanese archipelago comes under the strong influence of the continental high-pressure system, while the Siberian high-pressure system also gradually strengthens, causing temperatures to drop. In October, the direction of the seasonal winds shifts to the northeast, which is referred to as 'Minishi (new north wind)' in Okinawa.

During winter, the influence of the Siberian high-pressure system leads to strong northwest monsoon winds, resulting in cold and dry weather. In Okinawa, northeast winds are prevalent, and the strong winds can generate high waves.

While each region has its unique names and seasonal divisions, the Japanese archipelago as a whole experiences distinct seasonal weather changes due to the impact of migratory high-pressure and low-pressure systems and air masses.