The agency is calling for measures to prevent heatstroke.
The probability of average temperatures exceeding those of the average year is 50% in northern Japan, 60 per cent in eastern and western Japan, and 70 per cent in Okinawa and Amami. Forecasted precipitation is about the same or higher than the average year in western Japan and about the same level in northern and eastern Japan.
A La Nina phenomenon, in which sea surface temperatures near the equator become cooler than normal, is expected to occur off the coast of Peru, South America, from summer to autumn. As a result, the northwestward extension of the North Pacific High and the northeastward extension of the Tibetan High from the Chinese mainland will strengthen, bringing a possibility that the two will overlap over Japan. Air temperatures tend to increase when a high-pressure system extends to high altitudes.
