A method for inferring activities to a user is provided. The system receives at least one location trace and corresponding contextual information. The system then derives a set of venues based on a venue database, wherein a respective hypothetical visit is associated with the contextual information corresponding to the location trace. The system derives a set of activity types associated with a context based on the venues, the corresponding context indicated by the location trace, and a venue-to-activity mapping. In addition, the system receives a user query context and identifies a number of activity types of which the associated contextual information is similar to the user query context. The system further weights a respective identified activity type based on its associated context's similarity to the user query context, normalizes weights associated with each identified activity type, and produces an activity-type probability distribution, thereby facilitating inferring activities associated with the user.