Japan's convenience store sales rose 0.8 percent in August from a year earlier for the first increase in three months as temperatures helped boost sales of beverages and ice cream, an industry body said Friday.

Same-store sales at seven major convenience store operators totaled ¥936.3 billion ($8.7 billion), according to the Japan Franchise Association.

The number of customers declined for the sixth consecutive month, down 2.5 percent, due partly to poor weather in the latter half of the month, while average spending per customer grew for the 10th straight month as consumers tended to buy food in bulk before typhoons approached.

A rise in temperatures also pushed up sales of department stores in the month, up 2.3 percent from a year earlier on a same-store basis, as sales climbed for the first time in five months due to brisk purchases of summer clothes, the Japan Department Stores Association said.

There was solid demand for luxury items, such as kimono, as customers made last-minute buys ahead of a planned consumption tax hike in October, according to the association.