it's not just your local connection. whatever service you are trying to use at that time is the same service many many other people are also trying to use at that one time. it's just how it works. people get off work and after supper, enjoy some time online for game play (i assume this is what you are trying to do since it is just about the only thing people care about ping time with).
very few companies make/maintain enough servers to handle peak usage 24/7, so during these peek times, everyone suffers a little bit. it's cheaper this way for the company providing the service.