Was it pruned? The main cause of not blooming is pruning the flower buds off the year before.

No I didn't prune it at all.

Then here are some things that could have happened:

Low temperatures. The buds could be flower buds that froze. Early frosts are especially destructive. Plants harden off progressively in the fall. If a frost occurs before hardening is complete, the frost can kill flower buds. Flower buds can also be damaged by cold, dry winds, particularly when warm winter weather is followed by a period of bitter cold.

Bud blast. Disease may attack the buds before they open. If it is a fungal infection, the dead bud will be covered with short hair-like structures.

Fall Blooming. Some causes of fall blooming include a dry summer and moist fall and/or warmer climates including a warm fall. For some reason, fall blooming is more common in Georgia according to Dr. Sandra McDonald. Plants which are not sufficiently hardened off or are exposed to unseasonable warm spells can start bloom prematurely. These blooms are seldom satisfactory and many times get frozen before opening fully. In any case, the seasonal bloom is lost. Avoid application of nitrogen after late spring, but phosphorus and potassium may be applied throughout the growing season. Application of nitrogen too late in the season can hinder hardening off in the fall.

Drought. When soil moisture is too low, the buds will not open. Watering will usually resolve this condition if detected soon enough. Also, summer drought with a moist fall can contribute to fall blooming.

Deer Damage. Deer and rabbits may eat many of the flower buds as they browse in the winter, particularly if the weather is harsh and other food is scarce. Squirrels have been know to eat azalea buds.

Here is a link that might be useful: How to grow rhododendrons and azaleas.

Thanks for your indepth answer. I think it might be several things that you mentioned. Maybe early frost or drought.