Western Japan has experienced record-low rainfall since July, with precipitation levels falling to approximately 10% of the long-term average [1].
The extreme lack of rain threatens water security and agricultural stability across several prefectures. If the dry spell continues, the region faces a high risk of expanding drought conditions that could impact local infrastructure and food production.
The Japan Meteorological Agency said the rainfall deficit is the lowest ever observed in the history of records for Western Japan [1]. The shortage is most acute in the Shikoku region, where precipitation has remained below 10% of normal levels [2].
Meteorologists said the conditions are due to a persistent high-pressure ridge. This weather pattern has limited the passage of low-pressure systems that typically bring necessary rain to the region [1]. The affected areas primarily include Kyushu, Shikoku, and parts of the Chūgoku region [2].
In addition to the lack of rain, the region has faced extreme heat. The Japan Meteorological Agency said the country recorded five consecutive days of extreme heat for the first time [3].
Forecasts for the duration of the dry spell vary. Some reports suggest the conditions may persist for the next 10 days, while other estimates indicate the pattern could continue for approximately one month [2]. Local authorities continue to monitor reservoir levels as the region moves through August.
“Western Japan has experienced record-low rainfall since July”
The convergence of record-low precipitation and consecutive days of extreme heat creates a compounding crisis for Western Japan. By blocking the low-pressure systems that regulate the regional climate, the high-pressure ridge is not only depleting water reserves but also increasing the risk of wildfires and crop failure. The uncertainty regarding whether the drought will last 10 days or a full month complicates emergency water management and agricultural planning for the remainder of the summer.
