Years ago I lived out in the Southwest and when it was 95 degrees there...it felt cooler than the 95 degrees we get in Pennsylvania because the Southwest doesn't get that sticky and muggy humidity that we get here on the east coast. In addition to the humidity...our sunlight can be pretty blinding at times so sunblock is a necessity when spending time outdoors.
During the summertime we get hit with a lot of severe thunderstorms which include down pouring rain (sometimes inches of rain per hour), heavy lightning, high winds, roaring thunder, hail and sometimes we even get tornadoes here in Pennsylvania.
Although unlike the midwest, we usually do not get F3, F4 and F5 tornadoes...when we get them here in PA, they are usually weaker and in the F1 and F2 range. With that said...we can and do sometimes get stronger tornadoes but it's more rare for us than other states out in the midwest.
Pennsylvania is a great place to live during the summertime and even better yet...it's a great place to visit during summer vacations. For the most part...our weather is beautiful throughout the season but do be prepared for an afternoon rain shower or thunderstorm during the very hot summer days.