Google announced the June 2024 spam update on June 20 and marked it complete on the Search Status Dashboard on June 27, 2024, after 7 days and 1 hour. It was the second spam update of 2024, following the March 2024 spam update that had shipped alongside three new spam policies.
This was a standard, broad spam update improving the automated systems that detect violations of Google's spam policies. Search Engine Land reported it was not a link spam update and did not automate the site reputation abuse policy, which Google was still enforcing only through manual actions at the time. Sites whose rankings improved during the window may simply have benefited from competitors being demoted.
If your site dropped in the June 20-27 window, review Google's spam policies and remove anything that violates them. Spam updates are algorithmic, so no manual action appears in Search Console and there is nothing to file a reconsideration request for; improvements register as Google's systems recrawl and reassess the site, which can take months.