Or, Scott;
Vines by nature are fast, but early season is a ticket that I ponder continuously. Woody vines are obvious, but if the vine has to die to the ground each year for utility purposes, I suggest Humulus lupulus. As a herbaceous vine, it is very fast to get to the top in spring.(Seeing as how Morning glories, etc are only full-sized in July...)

Perhaps you should elaborate about the early-season requirement?

we have a pergola at our vegetable stand that we want to look nice by the first week of June which is when farm members start coming for their produce.
Hops is a great idea. i thought passiflora incarnata perhaps.

Scott

P. incarnata is amazing. And potentially rampant via long, deep subterranian runners. I love it but It may or may not be blooming (It should be big, at least) for your function. Here, it grows and grows until it blooms mid-late summer. Full sun helps blooming tremendously.

Clematis, if happy, could be perfect if it is that right variety and blooms en masse at that time of year.

If your ideas do not fruit by next year, go have a look around your town in early June to see what vines look best.

For a real car-stopper, I've seen that a bunch of Ipo. tricolor 'Heavenly Blue' is most effective. Use Direct sowing; I'm not sure when it would start blooming in your area, but it has a long and stunning bloom season.

Hope that helps some. (if not muddying the water!)