This has been happening to me for about a month now, and was perfectly fine prior. In fact before this latest patch it had finally gone away for a while, and now is back in full force.
My spikes are completely random (except a game I just played which was nearly constant 300-1200 ping all game once laning started), and make it so that I join a normal game just to find out if things are clear. Last hitting and juking/tower diving is impossible, so ranked isn't even a thought.
Time of day doesn't seem to matter ( I generaly play in the middle of the night CST), but my speedtests throughout this time have consistently been coming back perfect. I've been told by others this is a local server connection issue on Riot's end, as only some people are affected, but those that are have it BAD.
What is up?! I've had this issue before at least a year ago and it miraculously went away with 'some patch', but it's getting ridiculous....