If your job has anything to do with search, you might feel like Google changes every day. Don’t worry, it’s just your imagination — in reality, it’s more like 13 changes every day. We can’t chase every change, but the past 11 years can tell us a lot about where Google is headed.

In 2023, Google reported an astonishing 4,781 “launches”, up dramatically from the 350–400 first reported by Matt Cutts in 2009. From 2009–2023, Google made approximately 35,000 changes to search and ran millions of search quality tests.

While the pace of change has leveled out over the past four years, the numbers are still overwhelming. How can any marketer hope to keep up or disentangle it all?

The short answer is: yes, it is. Using data from our MozCast research project, we can take a bird’s-eye view of the past 11 years (over 4,000 days). Red areas represent “hotter” days with more day-over-day fluctuations in page-one Google rankings:

Click the image above to view a high-resolution version.

While, on average, the algorithm is getting hotter, the pattern of rising temperatures is complex. Some heatwaves can be tied to major, named events, like Penguin 4.0 (#2) in September of 2016, but others, like the unprecedented volatility of summer of 2017 (#3), remain unexplained.

The internet itself is constantly changing, too, and we have to remember that Google search results are a real-time phenomenon. They would change every day even if all of Google’s engineers went on vacation. One striking example is the WHO declaration of COVID-19 as a global pandemic in March 2020 (#6). The pandemic drastically changed search behavior and results, causing huge shifts in e-commerce vs. brick-and-mortar shopping.

Zoomed out, the past three years clearly show a return to hotter temperatures, including a historically overheated summer of 2023 (#8) that never really cooled off. Is Google warming inevitable at this point? Which of the thousands of changes is bringing the heat?

In early 2018, Google officially confirmed the existence of broad “core” updates and started publicly reporting those updates. Since then, there have been 22 named core updates, including four in 2024. Here are the ten hottest core updates, according to MozCast:

The four core updates in 2024 took four of the five top spots, with two 2023 updates and the August 2018 Core Update (AKA “Medic”) rounding out the top seven. Note that the August 2024 Core Update is a bit of an anomaly — its rollout overlapped with a reported five-day bug in Google rankings that was impossible to separate from the update itself.

While core updates, in general, seem to bring outsized ranking fluctuations, Google provides little guidance around the specifics of any given core update. Google has reasons not to be transparent, but, practically, these updates are complex and multipart and may be complicated by the use of machine learning in the core algorithm(s). What is clear is that core updates represent significant changes to the Google codebase, with lasting impact.

How has AI, currently in the form of Google Gemini, impacted the Google weather? In spring of 2023, Google launched the Search Generative Experience (SGE), built on Bard (and later replaced by Gemini). If you refer back to the 11-year heatmap, you’ll see this corresponds with the beginning of what looks like an endless summer. Did AI cause the current heatwave?

The simple answer is: no. The MozCast data reported here relies on logged-out Google SERPs, and the initial launch of SGE was only for opt-in, logged-in searchers. We theoretically shouldn’t have been able to measure any impact of SGE until May of 2024, when AI Overviews were released to all US searchers, looking something like this:

So, was this timing just a coincidence? It’s possible that SGE required deeper changes to the core algorithm(s) that impacted organic rankings. We can’t confirm that hypothesis, but I think there’s something bigger at play here. Large Language Models like Bard/Gemini and ChatGPT opened up an AI arms race in content marketing, making it easier than ever to churn out automated content cheaply and at better quality than previously available.

It’s likely that some of the “heat” we saw across 2023 was a result of opening Pandora’s box of machine-generated content. It’s also possible that the eight core updates in 2023–2034 were, at least in part, an attempt to close that box. That push and pull would cause ranking fluctuations in both directions. This is a plausible explanation, but it’s difficult to prove.

Ultimately, Google’s “weather” isn’t a natural phenomenon — it’s driven by human choices, reactions, and, occasionally, mistakes. Whether the changes are heuristic or machine-driven, they’re all driven by the same core philosophy and business models.

There is a force of nature behind Google warming, though, and that’s the pace of content creation itself. Content marketing is big business, and the pace of content creation has clearly accelerated over the past 11 years, very likely accelerated by automation (including AI). This forces Google to react faster, which causes content creators to react faster, on and on until the heat death of the universe, or until we quit and open a taco cart (seriously, let’s consider it).

Competition from LLM-based (“AI”) search engines, including ChatGPT search, is also forcing Google to move fast and break things, leaving the rest of us holding the pieces. It’s unlikely that this high pressure front is going to blow away anytime soon.

We can learn a lot from the past 11 years, but ultimately, we have to be able to adapt. More heatwaves and storms are inevitable, and they’re unlikely to slow down. I can only offer one comforting guarantee — as long as people need to find other people, places, and products, both search engines and search marketing will continue to exist.

For a full list of major algorithm updates back to 2003’s “Boston” update, check out our Google algorithm update history. For daily data on Google rankings flux and SERP feature trends, visit our MozCast SERP tracking project.