The June 2016 update has occurred on 3 different dates (June 1st 2016, June 8th 2016, June 21st 2016), significant fluctuations in organic results were noted on each of these dates. It is estimated that several algorithm versions were released, or a gradual rollout of the same algorithm.
The algorithm’s effects:
A drop / rise in rankings and organic traffic for various sites.
The appearance / disappearance of rich snippets.
Causes for rankings changes:
Google has confirmed that there was no penguin update released during June, and from tests conducted by surfers it appears that this update is not affected by the website’s backlinks.
The update’s effects were found to be linked to website quality (content, ads above the fold etc.), from this we can conclude that the update is related to website quality or content. If your website was affected by this update, it is recommended that you look into these two matters first.
A detailed analysis of the algorithm and its effect on different website can be found in the link below.