A method and apparatus for estimating whether or not a wireless terminal is indoors are disclosed. The illustrative embodiment employs a pattern classifier that is trained on a plurality of input/output mappings, where each mapping corresponds to a respective location, the output of the mapping is a Boolean value that indicates whether the location is indoors, and the input of the mapping is based on empirical and predicted signal data for the location. In accordance with the illustrative embodiment, a computer-executable program is generated based on the trained pattern classifier. The computer-executable program estimates whether or not a wireless terminal is indoors based on empirical data reported by the terminal, and on a location estimate for the terminal that might be crude or inaccurate (e.g., based on Cell Identifier [Cell-ID], GPS, etc.).