How often should you replace windshield wipers?

Wiper blades degrade from ultraviolet exposure, ozone, heat, road grime, and freezing, and the rubber hardens and develops micro-tears long before the blade looks obviously bad. Six to twelve months is the usual interval, shorter in regions with intense sun or heavy winter use. The reliable test is performance rather than age: streaking, chattering across the glass, squeaking, leaving unwiped patches, or a blade that skips instead of gliding all mean the edge has lost its ability to conform to the glass.

Treating this as cosmetic is the mistake. Visibility in heavy rain at highway speed is a safety system, and a blade that smears rather than clears turns a manageable downpour into a genuine hazard, particularly at night when oncoming headlights scatter through the film. Replacement is inexpensive, takes a few minutes, requires no tools on most vehicles, and auto parts stores will frequently install them free at the counter.

Habits that extend blade life and prevent damage. Lift the blades or use a cover when snow and ice are expected, since freeing a frozen blade by running the wipers tears the rubber edge. Never run wipers on a dry windshield, which abrades both blade and glass. Clean the blades periodically with a damp cloth to remove grit. Keep the washer reservoir filled with proper fluid rather than water, which freezes and does not cut through road film. And replace the rear wiper too, which is routinely forgotten and matters for reversing. If the glass still will not clear after new blades, the cause is usually a film of wax, oil, or road residue on the windshield itself, which responds to a dedicated glass cleaner or a clay bar rather than to another set of wipers.