One Hour Traffic Spikes

[BlueDanube]

I've noticed over the past few weeks that several of my (I believe) Panda/Penguin affected sites seem to receive a massive rush of traffic during a given hour in the early morning (GMT).

This doesn't occur daily by any means but it's in marked contrast to the traffic patterns either side of that hour. Typically during that one hour period the traffic volume will be 6-8 times that of any other hour that day.

Does any one know or care to speculate about the cause?. Any similar experiences?

[Sand]

Have you checked the global location of the visitors during the spiky period? It might be helpful to know if they're in your target area, or off in a different part of the world.

Edit: I haven't personally seen an hourly spike that big, unless it was a news-related query. Every other time, it's been an influx in foreign traffic (often times from India, for whatever reason).