Japanese supermarket operator Daiei has reported a 4% drop in same-store sales in the March to May quarter compared to the year-ago period, partly due to unseasonable weather.

Overall May sales slid 3% compared to a year earlier, following a 3% decline in April and a 5% drop in March, reported the Nihon Keizai Shimbun. The company had forecast a 1% drop in sales for May.

Also affecting sales was a new requirement for supermarket operators to display tax-inclusive prices from April. Daiei attempted to combat this effect by lowering many prices, which hurt overall sales, the Nikkei Report said.