A Core Update Before Halloween, And No Later Than December 12
Google will announce its next core update within 45 days of September 24, 2026, and no later than December 12. We put two-thirds odds on the first half of that window, which means an announcement before Halloween, while the September spam update is still rolling or just after it finishes.
This is not a hunch. It rests on two things Google’s own release history shows: a six-year habit of shipping a core update in November or December, and a pattern in which spam updates given a two-week rollout window have twice launched alongside a core update within a day. If no core update is announced by December 12, we will say so on December 13.
Google Has Shipped A Core Update In November Or December In Five Of The Last Six Years
The exception was 2022, when Google shipped a helpful content update and a link spam update in December instead. Every other year since 2020 has ended with a core update.
The second reason is the gap. The May 2026 core update finished on June 2. That is 118 days without a core update, the longest stretch of a year in which Google has otherwise been unusually busy: two core updates, a Discover core update, and four spam updates. March and May 2026 landed only six weeks apart. A search engine shipping at that pace does not go quiet for the last quarter.
The third reason is what Google said about the September spam update. The March, June and August 2026 spam updates were each announced with “a few days” and finished in three days or less. September’s was announced with “up to two weeks,” and when asked, Google confirmed the longer window was deliberate.
Spam Updates Either Pair With A Core Update Within Two Weeks Or Go Months Without One
We measured the gap from every confirmed spam update since 2021 to the next core update. Eleven spam updates have a completed pair. They split into two groups with nothing in between. Orange bars are spam updates that got a rollout window of 14 days or longer.
Five spam updates had a core update within two weeks: June 2021 (8 days), November 2021 (14 days), October 2023 (1 day), March 2024 (same day) and March 2026 (3 days). The other six had nothing for two to five months. The median across all eleven is 56 days, a number that describes none of them.
What separates the two groups is partly the rollout window. The two spam updates Google gave a two-week rollout in the Search Status Dashboard era, October 2023 and March 2024, both launched with a core update inside a day. The one long spam rollout that stood alone was August 2025, which ran 26 days and which Google itself described as unusual.
September 2026 is the first spam update of the year to get a two-week window. The three before it were “a few days” updates, and two of those three stood alone. In shape, September looks like October 2023 and March 2024, not like June or August 2026.
One more pattern. Of the four spam updates that launched in the fourth quarter, three had a core update in the same quarter: November 2021, October 2023 and December 2024. Only October 2022 stood alone.
The honest caveat: eleven pairs is a small sample, and Google has never said spam and core updates are scheduled together. The 2023 and 2024 pairings may be release engineering rather than policy. We are betting they are not a coincidence, and we are putting a date on it so the bet can be settled.
Five Calls On What The Update Does, Ranked By Confidence
A prediction about timing is only half useful. In the four days after the September spam update began, we tracked 100 established forums and 16 authority sites in Ahrefs. Ninety-nine of the 100 forums gained estimated US organic traffic, by a median of 45 percent. Twelve of the 16 authority sites lost it: Mayo Clinic down 22 percent, Wikipedia 18, The New York Times 13, Allrecipes 13, Healthline 11. Here is what that tells us to expect.
Forums Keep Their September Gains
Core updates since 2024 have leaned toward first-hand experience. A core update that reversed the forum rise would be reversing a direction Google has held for two years.
The Same Authority Publishers Lose Again
Health, recipe and finance sites carrying programmatic, syndicated or templated pages lost in September. A quality re-rank finds those pages first.
The Rollout Runs 12 To 20 Days
March took 12 days, May took 12, December 2025 took 18.
Small Independent Sites Gain, Large Aggregators Flatten
Small forums rose a median 66 percent in September; the biggest platforms rose 14 to 43. That is the shape Google has said it wants since August 2024.
AI Overviews Shift With It
Google has confirmed core updates affect AI Overviews. If forum threads gain again, expect more forum citations inside AI answers, not fewer.
We Publish The Table Either Way
Each call is scored against the same 116-site dataset on completion day, whether it flatters us or not.
Five Moves To Make In The Next Four Weeks
None of this is new advice. The point is to do it before the update rather than during it.
Take a baseline now
Export Search Console clicks, impressions and average position for the last 28 days, by page and by query, for every site you care about. On announcement day you will want a clean before and you will not have time to build one.
Find your third-party sections
Sponsored posts, coupon pages, guest content with outbound links, syndicated feeds. Site reputation abuse has been named in every spam policy update since March 2024 and it is the pattern most exposed in the September data. Noindex or remove anything you would not want a Google rater to read as yours.
Audit the templated pages
Location pages, programmatic comparison pages, thin category hubs. If a page exists mainly because a keyword exists, it is the kind of page that lost in September. Merge it, improve it or let it go before Google makes the choice for you.
If you run a community, moderate it
Forums gained across the board, but the exceptions were sites where the community was bolted onto a database or a news site. Clear spammed profiles and link drops in old threads so the gain lands on real discussion.
Do not ship structural changes during the rollout
Redirects, migrations and mass deletions between announcement and completion make diagnosis impossible afterwards. Freeze on announcement day and hold until Google marks it complete.
For agencies: set the client expectation now that a core update is likely before the year ends, that early movement often partly reverses, and that the useful comparison is completion day against the baseline, not day two against yesterday.
The Next Core Update Is The Only Scheduled Chance A Demoted Site Gets
That is the part most recovery advice leaves out, and it is why the timing of this call matters to anyone still nursing losses from March or May. Dileep Thekkethil, Stan Ventures’ spokesperson and head of content and SEO, puts it in three rules drawn from watching sites through every core update since 2020.
Recovery arrives on the next update, not before
“Sites hit by a core update almost never claw the traffic back between updates. The reassessment happens when the next core update runs. If you have spent the months since May making steady, incremental improvements that give Google positive signals about the site, this is the window where that work gets counted. If you have not, it will not be.”
Do not make major changes while it rolls
“Fluctuations during a rollout are often momentary. A page that drops on day three can be back on day ten, before Google marks the update complete. Sites that panic and start redirecting, deleting or rewriting mid-rollout end up unable to tell what the update did and what they did to themselves. Hold until completion, compare against your baseline, then act.”
Watch the two weeks after completion
“There is a pattern we have seen repeatedly: Google tends to tighten a few loopholes in the update roughly two weeks after it marks the rollout complete. Sites that gained by exploiting something the update missed can lose it then, and sites that were caught unfairly sometimes get relief. The completion date is not the final word. There is still a ray of hope in the fortnight after.”
How We Will Score This
A prediction nobody can check is an opinion. These are the rules we are holding ourselves to. The date is on the calendar: December 13, 2026, either way.
Where The Dates Come From
Update dates and rollout durations are from Google’s Search Status Dashboard ranking release history, which records every confirmed update since November 2021, and from Google’s announcements for 2020 and earlier. The gap analysis counts the days from each spam update’s announced start to the next core update’s announced start. Link spam updates are included as spam updates; reviews, helpful content and Discover updates are excluded. The Discover-only core update of February 2026 is excluded from the core count because it did not affect web search.
The forum and authority-site figures are from our September 28 study of 100 forums and 16 controls: Ahrefs Site Explorer daily estimated US organic traffic, subdomains mode, adaptive traffic, September 17 to 28, 2026, with change measured September 28 against September 24. The full report, method and appendix of all 116 sites is published separately.
Want The Same Data On Your Clients Before The Update Lands?
We run the baseline, the announcement-day pull and the completion-day comparison for agency partners, white label, so you are the one who saw it coming.
Dileep Thekkethil
AuthorDileep Thekkethil is the Director of Marketing at Stan Ventures, where he applies over 15 years of SEO and digital marketing expertise to drive growth and authority. A former journalist with six years of experience, he combines strategic storytelling with technical know-how to help brands navigate the shift toward AI-driven search and generative engines. Dileep is a strong advocate for Google’s EEAT standards, regularly sharing real-world use cases and scenarios to demystify complex marketing trends. He is an avid gardener of tropical fruits, a motor enthusiast, and a dedicated caretaker of his pair of cockatiels.
