Happy 4th of July! There's a TON going on across the area - hopefully you've got some exciting plans for the holiday! As far as the forecast goes, it doesn't get any more "summer-like" than today's: heat, humidity and PM storms.
Highs will rise into the mid 90s in the Upstate and near 90 degrees in the Mountains. The humidity will make it feel a bit hotter, so be prepared for heat index values ranging from the upper 90s to low 100s in Upstate spots.
Storms will begin to fire as early as 1 or 2 PM, mainly up in the higher elevations of WNC. I think the Upstate's storm chances won't start up until about 3 or 4 PM. We'll keep the thunderstorms around through the late-afternoon and evening... before things finally settle by 9 or 10 - just in time for the fireworks displays!
Storm chances will be in the 30-40% range, meaning they'll be pretty hit-or-miss in the Upstate (plenty of towns will stay dry) and a little more scattered in the Mountains. Any storm could produce heavy downpours and frequent lightning - and a strong storm or two could bring hail or damaging winds. If you're planning a picnic or barbeque, have an indoor backup space - but many areas won't have to use it.
Hope you have a fantastic holiday!!