Japan's weather officials say it will be hotter than usual across the country from June through August.

The Meteorological Agency announced a three-month forecast on Tuesday.

The agency predicts a hot summer due to warm and humid air flowing in Japan from the edge of a high pressure system in the Pacific. It adds that the ending of the El Nino phenomenon will strengthen the high pressure system.

Forecasters say that in June and July, temperatures will be normal or high in northern Japan. They expect high temperatures in eastern and western Japan and in the Okinawa and Amami regions. In August, temperatures will be high across the country.

The agency expects rainfall to be near-normal during the three months in northern and eastern Japan, and usual or more than usual in western Japan as well as the Okinawa and Amami regions.

It says that in June, Okinawa and Amami, as well as the Pacific side of western Japan, will have normal or above-normal rainfall. The agency says the rainy season appears to have started in Okinawa and Amami on Tuesday.

In July, weather officials expect similar trends for western Japan and the Pacific coast of eastern Japan.

For other areas, the agency says there will be normal rainfall for June and July.

In August, it expects near-normal rainfall nationwide.

Officials warn of very high temperatures in August if a La Nina pattern takes place. La Nina refers to lower-than-usual sea-surface temperatures in the equatorial Pacific Ocean off Peru.

Agency official Tanaka Shotaro says there is a 50 percent chance of La Nina occurring this summer, and the degree of heat will depend on conditions in the tropical zone.

He called on people to take precautions for heatstroke and heavy rain.