Storing Your Daily Coffee – It is important not to refrigerate or freeze your daily supply of coffee because contact with moisture will cause it to deteriorate. Instead, store coffee in air-tight glass or ceramic containers and keep it in a convenient, but dark and cool, location. Remember that a cabinet near the oven is often too warm, as is a cabinet on an outside wall of your kitchen if it receives heat from a strong afternoon or summer sun.
The commercial coffee containers that you purchased your coffee in are generally not appropriate for long-term storage. Appropriate coffee storage canisters with an airtight seal are a worthwhile investment.
Source: National Coffee Association USA