Some outflow moved through here (or warm front slipped a bit southward) with a wind shift out of the north-northwest. Temperature down to 80F after a high of 87F. Dew point down to 74F (peaked at 80F earlier).
Sea breeze worked inland with some cells developing with its passage, then outflow enhanced the sea breeze front. Given the environmental conditions in place, the cells are slow moving and are tending to back build.
More than 100 people treated there.
https://6abc.com/post/heat-related-injuries-reported-berks-county-pa-crowds-gather-see-historic-steam-locomotive-big-boy/19437280/