The price of newly harvested rice has surged 48 percent from a year earlier to the highest level in 31 years, reflecting a shortage caused by extreme summer heat that reduced the previous season's harvest, the farm ministry's data showed Friday.

The average price of unpolished rice sold by the National Federation of Agricultural Cooperative Associations and other supplier bodies to wholesalers was 22,700 yen for 60 kilograms in September, the Ministry of Agriculture, Forestry and Fisheries reported.

In Japan, rice from each year's harvest begins appearing on store shelves around September.

This year's price is the highest since 1993 when it reached 23,607 yen, according to data from the National Rice Exchange and Price Formation Center, though the ministry's data only goes back to 2008.

The price surged last month also as rising production costs, driven by inflation, combined with booming inbound tourism that drove up rice consumption.

The sharp rise followed consumer stockpiling that began in August after the weather agency issued its first-ever advisory about the increased risk of a megaquake along the Nakai Trough.