A method of reducing tropospheric effects in GNSS positioning, the method comprising: determining, by a GNSS receiver of an electronic device , a first location of the electronic device at a first time; determining a tropospheric delay by: determining zenith delays for geographical areas along a path of GNSS signal travel between a GNSS satellite and the first location of the electronic device for cells of a grid through which the path extends, the zenith delays determined using current weather information of the geographical areas, the geographical areas traversed by the path represented by the cells of the grid , the cells comprising a selected size, each of the cells having a corresponding one of the zenith delays such that the zenith delays correspond to the cells that represent the geographical areas; determining a distance over which a path delay is to be determined for the cells; determining the path delay for each of the cells by adjusting a respective one of the zenith delays for each of the cells based on an elevation angle of the GNSS satellite relative to the electronic device to provide a plurality of path delays; and summing the plurality of path delays to determine the tropospheric delay; using the tropospheric delay to determine, by the GNSS receiver of the electronic device , a second location of the electronic device at a second time; wherein the second location has a higher accuracy than the first location. determining, by a GNSS receiver of an electronic device , a first location of the electronic device at a first time; determining a tropospheric delay by: determining zenith delays for geographical areas along a path of GNSS signal travel between a GNSS satellite and the first location of the electronic device for cells of a grid through which the path extends, the zenith delays determined using current weather information of the geographical areas, the geographical areas traversed by the path represented by the cells of the grid , the cells comprising a selected size, each of the cells having a corresponding one of the zenith delays such that the zenith delays correspond to the cells that represent the geographical areas; determining a distance over which a path delay is to be determined for the cells; determining the path delay for each of the cells by adjusting a respective one of the zenith delays for each of the cells based on an elevation angle of the GNSS satellite relative to the electronic device to provide a plurality of path delays; and summing the plurality of path delays to determine the tropospheric delay; determining zenith delays for geographical areas along a path of GNSS signal travel between a GNSS satellite and the first location of the electronic device for cells of a grid through which the path extends, the zenith delays determined using current weather information of the geographical areas, the geographical areas traversed by the path represented by the cells of the grid , the cells comprising a selected size, each of the cells having a corresponding one of the zenith delays such that the zenith delays correspond to the cells that represent the geographical areas; determining a distance over which a path delay is to be determined for the cells; determining the path delay for each of the cells by adjusting a respective one of the zenith delays for each of the cells based on an elevation angle of the GNSS satellite relative to the electronic device to provide a plurality of path delays; and summing the plurality of path delays to determine the tropospheric delay; using the tropospheric delay to determine, by the GNSS receiver of the electronic device , a second location of the electronic device at a second time; wherein the second location has a higher accuracy than the first location. <EOS>