Which of the following is not an example of periodic change?

The changes which do not repeat themselves after a regular interval of time are known as non-periodic changes. Examples of non-periodic changes are - earthquakes, cyclones etc.

The blooming of flowers, the Occurrence of tides and the Occurrence of phases of the moon occur at a fixed interval of time. Hence, these are periodic changes.

Hence, Cyclone is not an example of periodic change.