The tables bellow  calculates an "average" temperature rise for the rotors under a single-stop event

The default values listed above are typical for an average  'sedan-type' vehicle

 Brake Rotor Temperature Calculator 

Car Weight (kg):                         
Rotor weight (kg - [all 4 rotors]):    

Initial vehicle speed (kmph):  
Slowdown speed (kmph):      

Average rotor temperature increase (C):

Feel free to change the values, and see how this changes the outcome.

Peak rotor temperatures can be at least twice as high as what is calculated . 
Higher rates of deceleration will increase the peak rotor temperature more since the braking system has less time to dissipate the heat generated.
Under multiple decelerations, the temperatures move progressively higher because the rotors do not have a chance to cool to ambient temperatures.