Window cleaning in winter when the weather is sunny - why that's not a good idea. All you need to clean glass surfaces is a clean, soft cloth, lukewarm water and a pH-neutral soap.
However, if the temperatures are too low, you should skip cleaning your windows in winter. If it gets milder outside again, it's time to clean the windows. It shouldn't be too sunny, as the water on the window panes evaporates relatively quickly in the sun.