1. A method performed by data processing apparatus, the method comprising: identifying a search query from a search query log that includes data specifying search queries corresponding to particular geographic regions; generating a geo-query count that represents a total number of times that the search query was received over a specified period in a geographic region; comparing the geo-query count to a corresponding expected query count for the search query in the geographic region, wherein the expected query count is a baseline number of times that the search query is expected to be received in the geographic region based on the number of times that the search query is received in a baseline geographic region that is different than the geographic region; determining that the search query has a geo-query count that exceeds the corresponding expected query count by at least a threshold amount; and classifying the search query as a local query for the geographic region.