Clear skies give way to a dangerous heat stretch in St. Louis, with heat indexes reaching 108 through Wednesday.

Boston will see a hot, mostly sunny weekend, with Sunday reaching 91 before storm chances return Tuesday and cooler weather arrives late week.

Saturday brings early storms, heavy-rain concerns and a second round later in the day before Pittsburgh gets a sunny Sunday break.

Cincinnati starts Saturday in fog before temperatures reach 90 and late-day storms roll in. A hotter Sunday and Monday lead into a stormier midweek stretch.

Cleveland gets a sunny break Saturday before evening storms return. A wetter, potentially severe pattern takes over Sunday night through Tuesday.

Columbus will reach 88 degrees Saturday before late-day storms return. Sunday looks sunnier, but a wetter pattern builds Monday through Wednesday.

Jacksonville faces a stormy Saturday with heavy downpours, lightning and dangerous rip currents before extreme heat returns next week.

Orlando's Saturday starts sunny and steamy before afternoon storms bring lightning, gusty winds and localized flooding concerns.

Charlotte will reach 92 degrees Saturday before a hotter stretch pushes highs to 95 next week.

New York City faces a hot, humid Saturday with a heat advisory, a high near 87 and a chance of afternoon storms.

Atlanta's Saturday starts clear, but heat and humidity build toward a 91°F high before spotty storms arrive late.

Baltimore will bake into the mid-90s Saturday through Tuesday, with afternoon thunderstorms returning and a possible cooldown late next week.

Tampa will see a hot, mostly sunny Saturday before afternoon thunderstorms arrive. Sunday brings even higher heat, while rain chances ease later next week.