Midsummers Day, or the beginning of Summer?

Today is the day the Sun stands still. Is this the middle of Summer (northern hemisphere), or just the beginning? It sure feels like the middle here in Georgia (92 f or so here to today), but technically the semantic summer starts at the solstice in the states (but not in some European countries and Japan).

The Bad Astronomer has covered this ground a number of times, and I, despite being from the states, agree with him - it's the middle.