The Google Search Console seems to have a bug in their Search Analytics report, specifically with the average position metric.
Many webmasters are claiming the average position metric in the search analytics report has taken a sharp dive since July 13. I have seen dozens of screen shots from webmasters showing proof of this decline, and I am able to personally replicate this in most of the Google Search Console profiles I have access to.
Here is a screen shot of the green line significantly dropping down; the green line represents the average position data:
So do not panic, many are seeing the same issue. We are trying to get confirmation from Google about this possible bug in the Google Search Console.
Postscript: This was not a bug, but rather a reporting change. For more details, see our updated story.