The LM35 datasheet specifies that this ICs are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature.
Tutorial available - http://goo.gl/fP5F4U
Calibrated directly in ˚ Celsius (Centigrade)
Rated for full -55˚ to +150˚C range
Low self-heating, 0.08˚C in still air
0.5˚C accuracy guaranteeable (at +25˚C)