The frequency of a web search query generally reflects the degree of people's interest in the subject matter. Search logs are therefore a useful resource for trend analysis. However, accessing search logs is typically restricted to search engine providers. In this paper, we investigate whether search frequency can be estimated from another resource, namely, Wikipedia page view of open data. As a result, frequently searched queries revealed remarkably high correlations against Wikipedia page view. This fact suggests that Wikipedia page view is effective for understanding popular web search trends happening around the world.