Are we required to maintain temperature logs for medication storage refrigerators and freezers?    

Any examples are for illustrative purposes only.

The Joint Commission does not specifically require temperature logs for refrigerators and freezers used for to store medications.  Standard MM.03.01.01 EP 2 requires that medications are stored according to manufacturer's instructions for use.   

A process must be in place to ensure appropriate temperatures are being maintained within the required ranges for the medications stored and identifies maintenance responsibilities. 
Organization should also have a defined process for the disposal of medication from a refrigerator or freezer which has deviated from the specified temperature range.

Consult with state and local authorities having jurisdiction to address regulations and requirements specific to your geographic location.

Reference
EC.02.06.01

Additional Resources
CDC Temperature Monitoring Best Practices for Refrigerated Vaccines 
CDC Vaccine Storage and Handling Resources
CDC Vaccine Storage and Handling Toolkit