Written by attorney Allister Rex Liao | Sep 28, 2013

California Drivers: When Must Your Headlights Be Turned On?

We all know that California law requires that you turn on your motor-vehicle headlights when it’s dark outside, but did you know California requires that you turn on your headlights when there’s rain?

How about snow? Or mist? Or fog?

In fact, California law requires headlights to be turned on whenever there’s “inclement weather." But, what does “inclement weather" mean?

** California Vehicle Code, Section 24400:**

"A motor vehicle, other than a motorcycle, shall be operated during darkness, or inclement weather, or both, with at least two lighted headlamps . . . ."

"Inclement Weather" Defined

(1) A condition that prevents a driver of a motor vehicle from clearly discerning a person or another motor vehicle on the highway from a distance of 1,000 feet.


(2) A condition requiring the windshield wipers to be in continuous use due to rain, mist, snow, fog or other precipitation or atmospheric moisture.

Bottom Line

Turn on your headlights when (A) it’s dark, (B) you can’t see clearly up to 1,000 feet, and/or (C) the weather conditions require windshield wiper use.

The goal is to make yourself more visible to others AND to increase your ability as a driver to identify hazards around you. Whenever in doubt, just turn on your headlights (low beam).

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