In Bangladesh, many deep abandoned wells, originally drilled for oil and gas exploration, have been used to extract valuable information about the subsurface geology and temperature of areas of interest. Analysis of the temperature data of these wells indicates that the average geothermal gradient varies from 19.8 to 29.5°C/km along the southeast part of the Bengal Foredeep region and from 20.8 to 48.7°C/km along the northwest stable shelf.