Supahos mentioned the load temps. Which is something you should do.
If you have an OC what is it? If its stock clocks what are your max temps?
I had 4670K I had on stock clocks and undervolted in the Summer and my averages for idle were around 31-37C. It would be easy to understand if your room was just slightly warmer and raised the idle temp.
Haswell is a little bit 'hotter' than the previous generation Intel CPUs . I suggest that you do that the other guys told you. Which means check the temperature room and run Prime95 and see when what is the max Temp and how your CPU reacts in intense activities ( without getting any errors from Prime95 ).
BUT, a very important aspect for the CPU temperature is the Airflow inside the case in general . The general idea is to push out of the case the hot air and pull inside the cool air . Take a look at this if you like: