The best cleaner for windows outdoors is Windex Outdoor Multisurface Concentrated Cleaner. I like it because it comes in a special bottle that you can hook up to your garden hose and spray directly on windows before cleaning.
One of the best and simple cleaners is vinegar. Just put one-half cup vinegar, along with detergent, in a gallon of hot water. If the window is quite dirty, you may need to wash with just soap and water first.
Use Windex Outdoor window cleaner, deffinitely the best for me. I have a dog and she likes to get dirty and then lick the windows and Windex always helps to clean up after that!
