Google announced the March 2023 core update on March 15 and marked it complete on the Search Status Dashboard on March 28, 2023, after 13 days and 7 hours. It was the first core update of 2023 and the first since the September 2022 core update, so the SEO community watched it closely.
Data providers tracked by Search Engine Land disagreed on scale but agreed the update was substantial. Semrush measured volatility increases 74% higher than during the September 2022 core update, with its sensor peaking at 8 versus about 5 in September, and found 8.7% of top-10 results had previously ranked beyond position 20, versus 6.5% for September 2022. RankRanger read it as roughly as volatile as September 2022 overall and among the biggest updates it had measured, topped only by the June 2021 core update, though with lower volatility inside the top 5 positions.
If your site moved in the March 15-28 window, Google's standing guidance for core updates applies: audit the pages that lost visibility against the self-assessment questions in the core updates documentation and invest in overall helpfulness; meaningful recovery typically registers at a future core update. Our recovery guide covers the sequence.