Refrigeration temp

If you are drinking them at that temp, and not letting them warm up a bit before sipping on, then that's your most likely offender. Let them warm, or bump up the fridge temp to about 45-48°. You'll still want to let them warm a bit, but the flavor right after opening will be closer to optimal temperature for tasting.

Also, it's much more likely that the fact that a week or two has passed that is affecting the flavor more than storage at a colder temperature. Some IPAs will retain their hoppy flavor longer, while some disintegrate rather quickly. Depends on the beer.

 

In general it is best to store them cold as it typically preserves them better. Do let them warm up before drinking though. Drinking any beer that cold will mask some of it's flavor because it effectively numbs some of your taste buds.

 

What others say. Fridge 46 - 48, and let them warm a minute with the proper glass.

 

I get more of a hop bite when I drink them cold. I like the balance of the hops and the malt. This usually happens for me several degrees below cellar temp.