The other day, I reported that many webmasters were noticing a decline in their average position metrics in the Google Search Console Search Analytics report. We thought it was a bug, but Google has now told us it is a feature change.
Going forward from July 14, 2017, the metrics may look different because of how Google measures the search results in the lower positions. Google updated the data anomalies page to say they made an "incremental improvement in Google's logging system now provides better accounting for results in lower positions." Google explained that "this change might cause increase in impressions, but also a decrease in average positions."
Of course, with any of these reporting changes, it has zero impact on your real rankings. Google explained "this change only effects Search Console reporting, not your actual performance on Google Search."
Gary Illyes from Google posted the news on Twitter adding "we've updated the product updates help center article with some details about the recent Search Analytics change."
Google now also added the "note" to the chart so this change is more visible:
This freaked out a ton of webmasters and it would have been nice to see the data anomalies page updated with this information prior to the change going out. Google is normally good about such updates but I guess one slipped through the cracks here.
Forum discussion at Twitter and WebmasterWorld.