Cool weather and the stagnant economy depressed sales at the nation?Ûªs largest retail chains in June and deflated May?Ûªs consumer spending kpree, analysts said yesterday.</br></br>Retailers said lackluster sales of weather-sensitive merchandise such' as air conditioners and apparel were partially responsible for the June slump.</br></br>?ÛÏMore importantly, the poor performance .of most retailers in June reflected the still sluggish economic environment, coupled with high interest rates,?Û? said Jeffrey Feiner, senior retail analyst at Merrill Lynch,</br></br>Analysts attributed the May buying surge to cabin fever on the part of frustrated but still cautious consumers who had been snowbound by unseasonable April storms.</br></br>?ÛÏWe do not expect to see any visible improvement in the retailing picture until the back-to-school selling season begins in mid-August,?Û? Feiner said. -Sears, the No. 1 retailer, said its sales for the five weeks ended July 3 dropped one percent to $1.85 billion from $1.87 billion in June 1981. Chairman Edward Telling blamed the decline on cooler weather and ?ÛÏexceptionally strong?Û? year-ago sales. Sears had a 7.2 percent gain in May.