Yes, both front fog lamps and rear fog lights (fog taillights) are legal in the state of California, provided you adhere to certain conditions. In fact, when it comes to both fog lamps and other after-market equipment, this state’s regulations are some of the most lenient.

However, fog lights cannot represent a substitute for headlights—if you need to turn on your windshield wipers, it is time for the perfect combo: fog lights and low beams.

When you cannot see clearly for 200 feet in each direction because of a curve, hill, rain, fog, or other reason, it’s time for headlamps – fog lights are only supplemental – only in case headlights cannot improve visibility should fog lights be turned on.

Keep in mind that, during inclement weather conditions, when you cannot recognize a person or vehicle from 100 feet away, California drivers must use their headlights. Moreover, during poor adverse conditions, low-beam headlights must be turned on. In case headlights do not provide sufficient lighting, fog lamps have you covered.

Legal Requirements for Mounting and Position of Fog Lights

As the California Code of Regulations specifies in Section 26103, when installing fog lights, make sure their lens is centered over their fog lamp bulb.

Keep in mind that they should be aimed so that the inner edge of the lens retaining ring must not be closer than 10 cm (4 inches) from the front turn signal lamp center when a vehicle is not loaded.

Just like in most states, California Vehicle Code 24403 forbids the installment of more than two fog lamps. In addition, in order to ensure a safe and well-lit road, the law requires that front fog lamps be mounted at a height of not less than 12 inches nor more than 30 inches from the ground.

However, California allows the installment of rear fog lights rear fog taillamps as well, as stated by Cal. Veh. Code § 24602, with the following requirements:

  • When installing two lamps, one must be put on the left side and one on the right side, both at the same level and as close to the sides as is reasonably possible.
  • When there’s only one rear fog lamp, it must be mounted as close as practical to the left side or to the center of the vehicle;
  • In addition, its mounting height can be between 12 inches and 60 inches;
  • These lamps shall be wired so they can be turned on only when the headlamps are on. In addition, they must be installed with a switch so that they can be turned off when the headlights are on;
  • The distance between the edge of the lamp’s lens and the edge of any stop lamp must be less than four inches.

What Fog Light Colors Are Legal in California?

When it comes to colors, California regulation is clear: the color of front fog lamps can be in the color spectrum from white to yellow (including amber, which is a reddish version of yellow).

In addition, except for headlights, all lamps and reflectors that may be seen from the front, sides, or the rear of a vehicle can have any unlighted colors as long as the emitted light falls within the mandatory spectrum.

Consequently, as long as these lights are turned to white while you’re driving, it would be acceptable to have them on the vehicle (assuming there is a white-light setting; if there is not, then the car with these lights cannot be driven on a public road).

Meanwhile, fog tail lamps can only emit a red color.

In case the unlighted color differs from the mandatory output light color, make sure that the lamps’ total affected projected luminous area, which is visible from the rear or mounted on the sides close to the rear of a vehicle, must be covered by the inner lens of the accepted colors.

Just like most U.S. states, has some clear rules in terms of forbidden lights in the case of passenger vehicles:

  • Flashing lights are prohibited;
  • Flashing amber warning lights, be they installed in the front, sides, or rear, can only be used by authorized emergency vehicles;
  • Steady burning, flashing white lights can be used on law enforcement vehicles;
  • Flashing and steady burning red lights can only be displayed by authorized vehicles or in cases of extreme traffic hazards.

Other Legal Requirements for Fog Lights

As Cal. Veh. Code § 24405 imposes, there can only be 4 front lamps turned on simultaneously, including headlights, auxiliary driving or passing lamps, for lights, warning lights, spot lamps, or gaseous discharged lamps;

No more than eight lamps may be installed in the vehicle for use as headlamps while it is being operated or driven off the roadway. Moreover, they must be wired independently of all other lighting circuits, and whenever the vehicle is operated or moved on a highway, they must be covered or hooded with an opaque hood or cover and turned on.

Can I Use Fog Lights During the Night in California?

Yes, but bear in mind that when driving a car at night or in poor light, the driver must use a composite beam of light that is high and intense enough to expose people and other cars at a safe distance in front of the car, according to the conditions and restrictions: in case you’re following another vehicle within 300 feet to the rear or when you are approaching oncoming traffic within 500 feet, you should use the lowermost distribution of light (sufficient light to detect people/ objects within 100 feet).

Although the California Driver’s Handbook recommends using high beams during nighttime driving, when possible (including dark city streets or open country), adding up fog lights to your high beams may have a counterintuitive effect: the light may bounce back into your eyes (and other drivers’), causing glare especially within 150 meters of you due to both their brightness and positioning.

As such, in case you need extra lights during poor weather, it may be best to combine your low beams with your fog lamps.