Search Console year over year comparisons stop at about four months. A comparison needs both periods stored, and Google keeps 16 months: four recent months plus the same four a year earlier use up the whole window. So when someone asks for 2026 against 2025, the report you need is already gone.
Month17 keeps the months Google deletes and answers year-over-year questions from Claude or Cursor.
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The four-month ceiling, worked out
Take June to September and compare it with June to September last year. The older half starts 16 months back, right at the edge of what Search Console stores. Add May and the comparison needs a month Google has already deleted. The date picker won't offer it, so the longer comparison never appears as an option.
The API has the same edge. It returns more rows than the UI, but it reads from the same 16-month store.
Reports the ceiling rules out
- The annual review: January to December against the year before.
- Peak season against peak season, once the season runs longer than four months.
- A site migration measured against the year before it, once the migration is more than four months old.
These are the comparisons people get asked for, and with Search Console alone each one gets answered with a shorter period or a guess.
How Month17 runs a year-over-year comparison
Month17 saves every performance row daily and never deletes any. Its MCP server has a year_over_year tool that takes a date range and returns it next to the same dates 365 days earlier, by query or by page. You see which queries gained clicks, which lost them, and how many.
In practice you ask Claude or Cursor something like "how did our top pages do this summer compared with last summer?" The model calls the tool and answers with the numbers attached.
Your first full-year comparison is eight months away
On the day you connect, Month17 backfills the 16 months Search Console still holds. The archive reaches 24 months eight months later, and from then on every year can be compared with the one before it.
Each month you wait delays that day by a month, and with it the earliest year you'll ever be able to compare. Early access is free, and the data loss calculator shows which of your months expire next.