While consistently high ping times can be bad you have to look at what you are measuring.
A ping measurement is a time for a packet to go to another server, be acknowledged and then return to you.
It is not a speed, it is travel time and it is an indication of latency.
Think of a ping as you going to your friends house in your car and back again. latencies would include stop lights and other delays. your friend could take time in answering the door 'cause he is busy on the phone or he could be waiting right behind the door for you to ring.
most of these factors have nothing to do with speed but would impact a neighbours observation of how long you took and may consider you slower.
in the case of the spikes you've seen it is the analogy of the friend being busy on the phone... you just had to wait at the door a little longer
in your example of your measurement there is nothing to worry about, the server you are pinging is just getting a little busier.