Modesto, CA Outdoor Lighting: Billboard Lighting (2026)
Key Facts
- Brightness cap
- 0.3 foot candles above ambient light
- Measurement device
- Foot candle (Lux) meter aimed at sign face
- Ambient reading window
- 30 min after sunset to 30 min before sunrise
- Malfunction default
- Automatic revert to black screen
- Governing section
- Modesto Code § 10-6.108(f)(1)(ii)(j)
- Applies to
- Message boards, video signs, freeway billboards
Summary
Modesto limits electronic message boards, video display signs, and digital freeway billboards along Highway 99 to a brightness of three-tenths of a foot candle above ambient light, measured with a Lux meter under Municipal Code Section 10-6.108(f)(1)(ii)(j). Every covered sign must run automatic dimming technology and revert to a black screen immediately if it malfunctions or exceeds the cap.
10)Illumination. Digital freeway signs shall operate at brightness levels consistent with Section 10-6.108 (f) (1) (ii) j). ... j)Brightness. Signs shall utilize automatic dimming technology to adjust the brightness of the sign relative to ambient light so that at no time shall a sign exceed a brightness level of three-tenths (0.3) foot candles above ambient light, as measured using a foot candle (Lux) meter and in conformance with the following process:1)Light measurements shall be taken with the meter aimed directly at the sign message face, or at the area of the sign emitting the brightest light if that area is not the sign message face...2)An ambient light measurement shall be taken using a foot candle meter between thirty (30) minutes past sunset and thirty (30) minutes before sunrise with the sign turned to black screen...4)The brightness of the sign conforms with the brightness requirements of this subsection, if the difference between the ambient light measurement and the operating sign light measurement is three-tenths (0.3) foot candles or less.6)Malfunction. All signs shall contain a default mechanism that will cause the sign to revert immediately to a black screen if the sign malfunctions.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 71).
Full Breakdown
108(f) of the Modesto Code of Ordinances regulates electronic message boards, video display signs, and digital freeway billboards as a single family of illuminated signage. 3 foot candles above ambient light, measured with a foot candle (Lux) meter aimed at the sign face. The code sets the measurement protocol step by step. 3 foot candles. Measurement distance scales with sign area, from 100 feet for signs up to 100 square feet to 250 feet for signs between 651 and 1,000 square feet. Applicants must submit lighting-engineer calculations with the building permit application demonstrating compliance, and every sign must carry a default mechanism that forces a black screen if the sign malfunctions.
3 foot candle ceiling governs both on-premise electronic displays and freeway billboards. Messages must transition instantaneously with no flashing, blinking, fading, rolling, dissolving, or animated effect, and audio is prohibited on every covered sign type.
Violations & Fines
A sign exceeding the 0.3 foot candle brightness differential, lacking the required automatic-dimming or black-screen malfunction default, or operating without the Board's conditional use permit is out of compliance with Section 10-6.108(f). The City's Community and Economic Development Department enforces sign standards through code enforcement, and a noncompliant sign can be ordered dimmed, modified, or shut off pending correction; operating an unpermitted electronic message board or digital billboard risks conditional use permit denial or revocation.
Frequently Asked Questions
How bright can an electronic message board or digital billboard be in Modesto?
Does the brightness limit apply to freeway billboards along Highway 99?
What happens if a digital sign malfunctions?
Sources & Official References
Other rules in Modesto
California rules heatmap·Compare Modesto to another location·View the California outdoor lighting overview
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