NEW YORK (CNN/Money) - Wal-Mart Stores Inc., the world's largest retailer, lowered its June sales forecast Monday, citing soft sales and unseasonal weather over the Father's Day weekend.

The Bentonville, Ark.-based discount chain said it now sees June comparable sales -- or sales at its stores open at least a year -- up 2 to 4 percent, compared to its earlier guidance of sales tracking at the low end of a 4 to 6 percent gain.

In a pre-recorded weekly update, Wal-Mart said Father's Day "was disappointing," with sales in key categories flat compared with the previous year. The retailer also blamed cooler-than-normal temperatures for hurting sales of its lawn & garden and pool products.

Among the best-performing product categories were food, paper goods, pet supplies and electronics.

Wal-Mart (WMT: Research, Estimates) is expected to report June same-store sales July 8.