Methods and apparatus are provided for adaptive thermal slope control for dynamic thermal management. In one novel aspect, the device monitors and obtains sampling temperatures, calculates a thermal-slope index, determines whether the calculated thermal-slope index is greater than a predefined slope threshold, adjusts a power budget based on a thermal-slope algorithm, and applies the dynamic thermal management (DTM) adaptively based on the adjusted power budget. In one embodiment, fixed slope algorithm is used. The power budget is adjusted such that an adjusted slope of temperatures stays at a constant. In another embodiment, the time prediction algorithm is used. The power budget is adjusted such that a predicted time to reach a predefined thermal threshold stays a constant. In one embodiment, the time-prediction algorithm is a time-to-target-point (T2TP) algorithm. The T2TP is obtained using a linear equation or a LOG equation.