If you have noticed changes in Google Search Console reporting with impressions and position data, that is to be expected.  Google made some changes to make searches with lower positions more accurate, which is reflected in the changes.

Google has posted an update in their Data Anomalies list, as well as including a notation when you look at your data in Search Analytics within Search Console.

July 14 – onward

An incremental improvement in Google’s logging system now provides better accounting for results in lower positions. This change might cause increase in impressions, but also a decrease in average positions. This change only affects Search Console reporting, not your actual performance on Google Search.

Many site owners were posting on Twitter that they were seeing what seemed to be fluctuations in Search Console data earlier this week, and Google confirmed the changes yesterday.