The number of hot days with a high temperature of 30 degrees Celsius (86 Fahrenheit) or above could more than triple in Japan by the end of this century if nothing is done to stop global warming, the Environment Ministry said on Friday.
On a national average, the number of hot days annually is expected to increase by 12.3 to 52.6 days in 2080-2100 from about three weeks in 1984-2004.
Hot days will total about six months each year in Okinawa and over three months in Tokyo.
The ministry said the average annual temperature in the last two decades of the 21st century will rise by 1.1 to 4.4 degrees Celsius from the 1984-2004 period.
The number of cold days with a high temperature below zero degrees Celsius will fall substantially, it said.
While more days are likely to have rainfall of below 1 millimeter, days with heavy rain also will grow. “Rainfall in Japan will become extreme, or something more like tropical,” the ministry said.
The government is to draw up a plan next summer to curb the impact of climate change on Japan’s economy and society.
Based on the latest estimates, the ministry will analyze the impact of climate change on agriculture and other sectors and write a report by this fall.