Today will be hotter and more humid than the 4th. An Excessive Heat Watch is in effect from noon until 8pm for the southern-most parts of the region, as heat index values could exceed 110 while a Heat Advisory remains in effect for the rest of the DMV, including DC, for heat index values from 104-109. There could be a spot PM thunderstorm, otherwise, most areas will remain dry under partly sunny skies before more shower/storms could slide in overnight. Saturday brings a cold front later in the day that will stall over the I-95 corridor, producing a few thunderstorms along and east of I-95. Sunday is mainly dry and not as humid behind the cold front.