This happens with all games but is the worst with League Of Legends. I start a match and I just see my ping go from the normal 70-90 to 1000-4000 at different times. It will be fine for a while and then randomly it will spike to the high numbers I said above. I ran the command ping google.com on my computer and on a family members laptop in another room in the numbers were around the same. Here is a screenshot: http://i.imgur.com/x6fY92A.png
Keep in mind this was about 5 minute after a match (of league) ended. It was a lot worse when it was an actual game. There was almost no 70-100 pings just 100 and up. My computer is hooked up to ethernet and the other computer (That the screenshot is from) was in another room on wifi. What could be causing this?