It is relatively close to an AC vent, so that might be it. The load temperatures seem right though. I've used this GPU and block for 2 years plus, but the stable ambient temp and AC is new, so it's behaving a little differently. Thanks guys, I think being closer to the AC vent explains it.
It'd have to be sitting right on top of the vent and it pointing directly at the cpu core. Even then it shouldn't show that much of a difference while running. Are you looking at the cpu temp onboard sensor or a coolant thermocouple? If you are reading the temp from the cpu itself, there is something else wrong. Bad sensor or something like that. If you are reading the coolant temp at the block, then it is possible the a/c vent blowing on it could make a difference. If you are reading the coolant temp, that cold air being drawn through the radiator could account for the difference.