Lagging for literally no reason

I'll be playing a bunch of matches and then all of the sudden one match I will start lagging for no reason. Nothing changed, no new applications opened. Just start lagging and there's nothing I can do about it but wait for the match to end and then log off the game even if I wanted to keep playing (and hope it's fixed tomorrow).

My ping will jump to 200-500 and this will happen very frequently throughout the entire game, making it pretty much unplayable. I believe an easy solution to this is for Riot to fix the game, but we'll have to look into that.