After doing some parses this afternoon on the cluster of three dummies at Whiterim in Coerthas I came to the realization that there is never a reason to use Fire II over Blizzard II.

To give some background on the processes that I tested, I did four different rotations;

The first rotation was just pure Blizzard II. And it had a stable dps of 320.

The second rotation was Fire III> Fire II> Fire II> Fire II> Fire II> Blizzard III> Blizzard II. Which had a stable dps of 260

The third rotation was Fire III> Fire II> Fire II> Fire II> Fire II> Blizzard II> Blizzard II> Blizzard II. Which had a stable dps of 250

The fourth rotation was Fire II> Fire II> Fire II> Fire II> Fire II> Fire II> Blizzard II> Blizzard II> Blizzard II. Which had a stable dps of 250.

There is very little reason anyone should ever be using Fire II.

(Disclaimer; I am aware of the Blizzard II> Blizzard II> Fire III> Flare combo. This test was purely to gauge the efficacy of Fire II.)