Google updated their Data Anomalies page within Google Search Console to include information about a reporting issue for image search.

On October 6, Google is reporting lower impressions and click data for image search results, and they note this is particularly apparent for sites with a lot of traffic coming from image search.

October 6

Logging anomalies occurred in image search results, resulting in a decline in impression and click data. This is especially noticeable on image driven sites.

What is interesting about this is that nobody seems to have noticed the drop in impressions for image search data.  There was no chatter on various webmaster forums nor are there any posts on Google’s own Webmaster Help forums.

If you did happen to notice a drop in impressions and click data, this is why.

Because Google just lists a single date, it appears that it has been resolved now.

Because this didn’t show up on the Data Anomalies page until this week, it would seem webmasters can expect a week or two lag before issues are added to the data anomalies page.