We were very lucky on the day of our visit as the weather was beautiful and, in spite of the "bergy bits" and "growlers", we made a close approach to the face of the glacier where the Captain spun the ship so that everyone had a good view of the ice. Some claim that viewing a glacier is better on an overcast day as the deep blue of the ice can be better seen. That may be true, but the hot sun beating down on the ice face causes more frequent "calving". That day the thunderous sound of ice separating from the glacier face was constant and loud.
The weather in front of Hubbard is quite changeable - we have been there in rain, in fog so thick it would hide and entire cruise ship and in temperatures so cold you would think you are standing in a walk-in freezer. Glaciers like this are so large they generate their own weather and the run in to the face of the ice takes the ship through strong, cold winds blowing off the glacier and straight at an approaching ship. It's not until you are within miles of the glacier that the ship finds calm air and, if the sun is out, far warmer conditions.
If you are going to be visiting Hubbard Glacier, bring something warm to wear, It may be warm in the rest of Alaska, but standing in front of a 6 mile wide glacier is like standing in front of the largest air conditioner in the world!