Rain is expected to begin around noon in southern Kyushu and spread to Shikoku by night on Tuesday, May 19, 2024 [1].
This weather shift signals a transition in regional conditions as a weakening high-pressure ridge allows humid air to penetrate from the south. The interaction of these systems is driving both precipitation and a significant rise in temperatures across the archipelago.
According to the Japan Meteorological Agency, as reported by TBS News Dig, the influx of humid air is the primary driver for the forecasted rain [1]. The agency said that while mornings may remain sunny for much of the country, the weather will deteriorate in the south. TBS News Dig said that rain is expected to begin around noon in southern Kyushu and will likely reach Shikoku by the evening [1].
Temperatures are climbing rapidly across various cities. Many locations are forecast to reach approximately 29 °C [1]. Specifically, the predicted high temperatures for Sendai and Niigata are both 29 °C [1]. In contrast, Sapporo is expected to be cooler with a predicted high of 18 °C [1].
Recent data indicates a widespread heat trend. In Toyooka, Hyōgo, and Hita, Ōita, the highest recorded temperatures reached 35.3 °C [2]. This heat is not isolated to a few peaks; 313 out of approximately 900 observation points recorded maximum temperatures of 30 °C or higher [2].
Local reports emphasize the need for preparation. Livedoor News said that rain clouds are likely to cover southern Kyushu [3]. The shift in pressure systems continues to influence the movement of moisture, which will dictate the timing of the showers across the southern islands, and the main islands' coastal regions.
“Rain is expected to begin around noon in southern Kyushu and to spread to Shikoku by night”
The convergence of a weakening high-pressure system and an influx of southern humid air creates a volatile weather pattern characterized by sudden temperature spikes and localized precipitation. This pattern is typical of the transition into the rainy season in Japan, where high humidity often precedes significant rainfall, impacting daily transit and agriculture in the southern regions.
