Japanese weather officials are warning of possible heavy rains and extreme heat in western and eastern parts of the country from July through September.

On Tuesday, the Japan Meteorological Agency released its three-month forecast through September.

Agency officials say a high over the Pacific to the country's south will extend further west than usual, causing warm and humid air to flow from Japan's west to its east.

The latest information led the agency to revise its July forecast released last month.

Officials now expect "average or above average" rainfall across wide areas, instead of just "average."
They expect mostly average rainfall next month throughout the country's north, as well as in the southwest region of Okinawa and Amami.

Japan's rainy season normally lasts until late July in most regions.

The officials expect mostly average rainfall across the country in August and September.

As for reasons for their forecast, they cite a stronger high-pressure system over the Pacific, due to reduced storm activity over the Indian Ocean and the influence of El Nino.

The officials are warning a warm air mass due to El Nino and global warming will lead to extreme summer heat in eastern and western Japan, as well as in the Okinawa and Amami region.

The agency said that in the past humid air from an extended high-pressure system over the Pacific has brought heavy rains.