I agree with Robert. It's not DNS. Probably just the amount of traffic. That can be caused in a number of ways.
If you're ever interested in how the Internet as a whole is doing, go here:
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It can be a good indication if there are issues. Remember that if a major router is down, traffic usually gets shuffled off somewhere else & that can lead to delays. Sometimes it's as simple as your signal hitting a critical number of hops; more than 15 and you generally start to notice it (actually, it's an accumulation of time between hops & a couple of slow hops can make 6 or 8 too many). Other times, it's just that too much traffic gets re-routed to other major points. That sort of thing has been getting to be less of a problem over the years as the hardware gets 'smarter', but can still be a pain if the point is big enough.
A couple of years back, someone dug up one of the major fiber feeds near Chicago. We had issues with our sites in California (we're east coast US) for several days solid & then intermittently for weeks.
Aquisitions are a major source of delays, too. When Algx bought IDS (?), they changed all the routing schemes on the old network. We had issues for several days before things settled down & the tables all sync'd up. Usually, you don't get a delay due to this, just 404's, but delays can be part of it.
Major events can also clog the connections - so blaming it on the Pope might not be too outrageous. Residential Comcast customers usually notice a 3pm slow down. That's when all the kids get home from school & suddenly hit the network.
Jim