Ping Troubles

A friend and I have recently gotten into lol and we enjoy playing. However, recently my friend has been having 300+ ping in many of our games. One game and he'll have an easy 40-ish ping, then the rest of the games we play he spikes up to 300+. It is definitely not his connection because he always has 15-30 ping in discord. Need help fast to fix this problem because it's getting to be so much of a problem that he may never play league again.