"Fred" (Unconfirmed) — March 8, 2017
Google rolled out what appeared to be a major update, with reports of widespread impacts across the SEO community. Gary Illyes jokingly referred to is as "Fred", and the name stuck, but he later made it clear that this was not an official confirmation.
Unnamed Major Update — February 6, 2017
Algorithm changes beginning on February 1st continued for a full week, peaking around February 6th (some reported the 7th). Webmaster chatter and industry case studies suggest these were separate events.
The February 7, 2017 Google Algorithm Update – Analysis and Findings From A Significant Core Ranking Update (GSQi)
Unnamed Major Update — February 1, 2017
There was a period of heavy algorithm flux starting around February 1st and peaking around February 6th. It is unclear whether this was multiple algorithm updates or a single update with an extended roll-out, but anecdotal evidence suggests at least two updates.
Intrusive Interstitial Penalty — January 10, 2017
Google started rolling out a penalty to punish aggressive interstitials and pop-ups that might damage the mobile user experience. Google also provided a rare warning of this update five months in advance. MozCast showed high temperatures from January 10-11, but many SEOs reported minimal impact on sites that should have been affected.