The Japan Meteorological Agency said that the Amami region of Kagoshima Prefecture has entered the rainy season [1].
This onset marks a rare shift in seasonal patterns for the region. While Okinawa typically leads the nation in the transition to the rainy season, the Amami region was the earliest in the country to enter this year [1].
According to the agency, this is the first time in seven years that the Amami region entered the rainy season before the Okinawa region [1]. The agency said that the Amami region of Kagoshima Prefecture "is believed to have entered the rainy season" [2].
Data regarding the timing of the onset varies across reports. One source indicates the start was nine days earlier than average [1] and two days earlier than last year [1]. However, other reports say that the Amami region entered the season nine days later than average [6] and three days later than the previous year [7].
Both the Amami and Okinawa regions were officially noted as having entered the rainy season on the morning of June 21, 2024 [2]. The agency said that the typical end of the rainy season for the Amami region occurs around June 29 [5].
Agricultural and infrastructure planning in these southern regions depends heavily on the timing of these rains. The shift in precedence between Amami and Okinawa may indicate fluctuating atmospheric pressure patterns in the East China Sea during the early summer months.
“The Amami region was the earliest in the country to enter this year.”
The reversal of the typical sequence between Okinawa and Amami highlights an anomaly in the regional climate. Because the rainy season dictates water availability for agriculture and increases the risk of landslides and flooding, a shift in the onset timeline requires local governments to adjust disaster preparedness and farming schedules.
