For a seasonal keyword like "ski" or any other keyword that you may track in your Searchmetrics projects, you may see a slight difference in our Search Volume metrics and what is in the Google Keyword Tracker tool.
For this example, we're going to look at the search volume metric for the keyword ski from the Research area of Searchmetrics. Login to your account and go to the Keyword Discovery.
Type in the keyword ski into the search text field and the following results are shown (this screenshot was taken on February 21, 2020 so your results may vary).
The average monthly Search volume for this keyword is 37.894 in Searchmetrics on this day.
It may happen that Google shows a different search volume. Why? Moreover, Searchmetrics gets their Search Volume metrics directly from Google which makes it even more difficult to understand.
The answer is pretty simple. Searchmetrics takes a running average of the last 12 months to ensure that we provide the most accurate metric. If you look at the seasonal trend for the keyword 'ski' you'll see that there is a spike in search volume during the winter months.
Using a rolling 12 month average removes the variability of seasonality or major holidays where you would see drastically different search volumes month over month.