I think these graphs are just too unreliable. If I set it to Past 90 Days, there's a blip on Sept 6, 2025 with a value of 28. The next data point isn't until Nov 27, 2025 and it goes up to 100. If I then set it to Past 12 Months, the only data is in Nov and there is nothing for Sept.
Then, even more interestingly, if I change it to "News Search" (instead of Web Search) and set it to Past 12 Months, the biggest spike is actually May 18-24, 2025 where the value is 100 and the Nov blip is only 9.
https://trends.google.com/trends/explore?geo=CA&gprop=news&q...EDIT - that was set to Canada. If I set it to Worldwide the values change obviously.