Too much difference in the sensor value compared to the actual temperature value

In “Sending the SMS when the temperature crosses the threshold value” section the actual room temperature was found to be 27 degree celsius. But the sensor value was found to be 330. Which when calculated by the formula we get 32.22 degree celsius.
Why there is so much difference between the 2 values???

I guess the temperature value is in Kelvin, so 27 is around 300.15 kelvin.

27 degree celsius as shown by the mobile.

The value shown by your mobile might be the average temperature of your living area, so there will be difference in temperature inside and outside of your living.