The best time to get your windows cleaned is when they need it.  There is no such thing as a better time of year to get your windows cleaned.  If it rains after you've just had your windows cleaned you'll find that for the most part your window stays clean afterward,  Rain mixed with dirty window equals spots.  Rain mixed with a clean window equals a clean window.  But even still, we have you covered at A B Window Cleaning.  We are THE ONLY WINDOW CLEANING SERVICE IN THE TEMECULA VALLEY WITH A 30 DAY RAIN GUARANTEE!!  So go ahead and schedule your window cleaning during the rainy season.  We've got your covered!  Also, The longer dirt , grime and hard water sit on your windows the more chance the glass will be damaged over time.  Over time the sun can actually "bake into the glass with hard water spots, stains or screen burn in that will not come off even after a cleaning.  Your windows are one of the largest investments in your home.  The investment in a regularly scheduled window cleaning is a drop in the bucket compared to having the windows replaced.