Key Facts
• On July 22, the Japan Meteorological Agency released a 3-month weather forecast.
• Nationwide temperatures from August to October are expected to remain above average.
• Northern Japan may experience normal to above-average rainfall due to low-pressure systems.
• Sea surface temperatures are low in the central equatorial Pacific but high near the eastern Indian Ocean and east of the Philippines.
• Cumulonimbus clouds are likely to form frequently near the eastern Indian Ocean and east of the Philippines.
• The jet stream is expected to flow further north than usual, strengthening the Tibetan High.
• The Pacific High is forecasted to intensify southeast of Japan, contributing to warm air coverage.
• August: Northern Japan will see weather changes every few days, while other regions will have more sunny days.
• September: Northern, eastern, and western Japan’s Sea of Japan side will experience periodic weather changes.
• October: Northern and eastern Japan’s Sea of Japan side, as well as Okinawa, will see periodic weather changes, while sunny days will decrease on the Pacific side.
Summary
The Japan Meteorological Agency predicts continued high temperatures across Japan from August to October, with particularly severe late-summer heat in Kanto and western regions. Northern Japan may experience normal to above-average rainfall due to low-pressure systems and moist air. Sea surface temperatures and atmospheric patterns, including a northward-shifted jet stream and intensified Tibetan and Pacific Highs, are contributing to these conditions. August and September will bring more sunny days to eastern and western Japan, while October will see fewer sunny days on the Pacific side. These forecasts highlight the need for heat-related precautions and awareness of potential weather changes.
