City Council
Staff Report
From: City Manager
Report Type: ACTION ITEMS
Lead Department: Planning and Development Services
Meeting Date: December 8, 2025
Report #:2511-5569
TITLE
REINTRODUCED FIRST READING: Adoption of an Ordinance Updating Palo Alto Municipal Code (PAMC) Section 18.40.250 (Lighting) of Chapter 18.40 (General Standards and Exceptions) and Amending Chapters 18.10, 18.12, 18.28, and Section 18.40.230 of Title 18 (Zoning) to Adopt New Outdoor Lighting Regulations; CEQA Status — Exempt pursuant to CEQA Guidelines Section 15308 (Actions for Protection of the Environment)
RECOMMENDATION
Staff recommend the City Council adopt the Draft Ordinance updating Palo Alto Municipal Code (PAMC) Section 18.40.250 (Lighting) of Chapter 18.40 (General Standards and Exceptions) and Amending Chapters 18.10, 18.12, 18.28, and Section 18.40.230 of Title 18 (Zoning) to adopt new outdoor lighting regulations.
EXECUTIVE SUMMARY
Note: This report has been updated from its initial November 10, 2025, publication to incorporate a recent ordinance change that expressly exempts select public facilities, as discussed in the analysis section.
The draft Lighting Ordinance (Attachment A) implements part of one of the City Council’s priorities (No. 18, Council consideration of an ordinance implementing Bird Safe Glass & Wildlife Light Pollution Protections standards) and is consistent with Comprehensive Plan policies (including Policies N-1.9, N-3.3, and N-7.5). The draft ordinance, which has been modified based on City Council direction on April 7, 2025, aims to reduce light pollution and align with Dark Sky principles in order to increase the health and well-being of Palo Alto residents, protect wildlife and natural ecosystems, and reduce light pollution. The City Council’s direction at the April hearing aligned with the Planning and Transportation Commission (PTC) recommendations from October 2024, including requiring that new standards apply to replacement of existing lighting; allowing additional exceptions; and increasing efforts to raise awareness, which may help reduce the number of complaints and reliance on code
enforcement. In addition, the City Council requested that requirements be included for already- installed existing lighting to comply with the new lighting standards after a set time period.
The City does not have sufficient resources to proactively enforce the ordinance; staff will respond to egregious violations as capacity allows and will rely on outreach and community- based compliance measures to support implementation.
BACKGROUND
Early this year, Council identified 2025 City Council Priorities and Objectives. Under the Climate Action & Adaptation, and Natural Environment (CA) category, the City Council directed staff to prepare an ordinance implementing wildlife light pollution protections standards (2025 Council Priority #18).
Lighting and DarkSky International
The term “dark sky” generally refers to movement and achievement of significant reduction in light pollution so that the sky returns or becomes closer to its natural nighttime darkness.
Jurisdictions can implement regulations to decrease light pollution, and many cities have adopted “dark sky” ordinances to reduce light pollution. Advocates of “dark sky” policies cite a number of advantages, including:
1. Support of the body’s natural circadian rhythm, promoting better sleep.
2. Reduction of glare, improving safety and comfort at night.
3. Protection of nocturnal species, who rely on natural darkness for navigation, mating cycles, and foraging.
4. Support of plant cycles, which rely on periods of light and darkness.
5. Conservation of energy, by only using what light is necessary.
6. Reduction of light pollution, enhancing the beauty of the night sky.
DarkSky International is a recognized worldwide authority combatting light pollution.1 The organization publishes guidance for communities seeking to achieve a “dark sky” and decrease light pollution. The framework focuses on principles, which have been incorporated into the proposed ordinance:
1. Useful: Use light only if it is needed. All light should have a clear purpose. Consider how the use of light would impact the area, including wildlife and their habitat.
2. Targeted: Direct light so it falls only where needed. Use shielding and careful aiming to target the direction of the light beam so that it points downward and does not spill beyond where it is needed.
1 Link to the DarkSky International Website: https://darksky.org/who-we-are/advocates
3. Low Level: Light should be no brighter than necessary. Use the lowest light level required. Be mindful of surface conditions, as some surfaces may reflect more light into the night sky than intended.
4. Controlled: Use light only when it is needed. Use controls such as timers or motion detectors to ensure that light is available when it is needed, dimmed when possible, and turned off when not needed.
5. Warm-colored: Use warmer color lights where possible. Limit the amount of shorter wavelength (blue-violet) light to the least amount needed.
Previous City Council Discussion
On April 7, 2025,3 staff presented its recommendation for the Lighting Ordinance update, which differed from the Planning and Transportation Commission’s recommendation of October 30, 2024. Staff clarified that its recommendations primarily centered around concerns regarding impacts on enforcement and implementation once adopted. After deliberation, the City Council directed staff to return with several modifications, including requiring that new standards apply to replacement of existing lighting; allowing additional exceptions; and increasing efforts to raise awareness. These modifications aligned with most of the PTC recommendations and included requirements to be applied to all existing lighting, similar to the City of Brisbane. The City Council motion and staff analysis is provided below.
ANALYSIS
On April 7, 2025, the City Council directed staff to revise the draft ordinance for greater consistency with the recommendations made by the Planning and Transportation Commission in October 2024. The City Council’s motion items are italicized below, and staff descriptions on how each was incorporated into the draft ordinance follow each element of the motion:
MOTION:
A. Ensure protections in the existing code are not eroded for existing outdoor lighting in all zoning districts.
a. Retain the Requirements and Guidelines that the current municipal code provides to riparian ecosystems section 18.40.140.
No revisions needed as the updated ordinance provides equivalent or greater protection from light pollution compared to the existing outdoor lighting requirements. Additionally, the existing provisions and requirements in PAMC
18.40.140 will remain until the Stream Corridor Protection Ordinance Update is adopted.
3 Link to the City Council agenda for the public hearing on April 7, 2025 (Item #17):
https://cityofpaloalto.primegov.com/Portal/Meeting?meetingTemplateId=16024 B. Require this ordinance apply to all new or replacement outdoor lighting consistent with the Planning and Transportation Commission (PTC) motion of October 30th to include:
a. Installation of new outdoor lighting, replacement of existing outdoor lighting fixtures, or changing the lighting type or system;
Incorporated in Section 18.40.250(c). The language from the motion was added to the applicability section.
b. for replacement lighting fixtures on buildings and structures, develop a hardship exception provision that would consider technical feasibility or financial burden to only apply to replacements on existing buildings and structures; and Incorporated in Section 18.40.250(j)(2). An exception can be requested if implementation of the lighting requirements more than doubles the cost of the project.
c. any existing nonconforming lighting after 10 years for residential and 5 years for nonresidential shall remain extinguished until brought into compliance with this ordinance.
Incorporated in Section 18.40.250(l). The deadline for existing lighting to comply with the new requirements is five years from the effective date of the ordinance for nonresidential zoning districts, and 10 years for residential and mixed-use zoning districts. Any existing lighting that has not been brought into compliance with the Code by these deadlines must remain extinguished (off) until it meets the new lighting standards.
C. Existing luminaires that have the technical capacity to be adjusted to comply with the ordinance without a need to change the fixture should comply within two (2) years of the effective date of the ordinance (i.e: fixtures that have existing dimmers, adjustable directionality, timers, Correlated Color Temperature adjusters, motion sensors, etc.).
Incorporated in Section 18.40.250(l)(2). The deadline for existing lighting to comply through use of existing features is two years from the ordinance's effective date. That lighting will be required to meet the new standards, with the exception of the shielding requirements.
D. Amend Section (4)(A) to include specific application of the curfew to all new, replacement, and existing outdoor luminaires.
a. Citywide and Holiday lighting curfew of midnight.
Incorporated in Sections 18.40.250(d)(4) and 18.40.250(e)(4). The lighting curfew provision was revised to extend the turn-off time of all outdoor lighting to 12:00 a.m. Additionally, the seasonal lighting exception language was revised to explicitly state when such lighting is subject to extinguishment.
E. Implement the October 30th PTC motion regarding light trespass to change the light trespass from 0.5 to 0.1 foot candles at every reference throughout the ordinance.
Incorporated throughout the ordinance.
F. Incorporate into Section 1.B. Findings and Declarations, and Section 2 (a) Purpose, the Five Principles for Responsible Outdoor Lighting. One of the sections should include the full language of the principles.
Incorporated (Section 1B of the ordinance, and Section 18.40.250(a)(1)).
G. Develop an exception for special security concerns.
An exemption has been incorporated in the draft ordinance (Section 18.40.250(d)(7)) to address this direction, however without use of “special security concerns.” See below for further discussion of the specific approach presented.
H. Staff to return with recommendations on compliance mechanisms that would reduce the need for code enforcement – such as self-certification under business licenses, education through Utilities inserts, and potential adoption of a tool similar to Brisbane’s Good Neighbor Letter.
Potential measures are explained below for the City Council consideration, along with the pros and cons for each measure.
Exception for Special Security Concerns
During the April hearing, the City Council heard concerns from a community member about how the proposed new lighting standards might impact security, especially in their neighborhood along Edgewood Drive. A speaker noted that less or limited lighting could worsen existing security concerns for property owners in the neighborhood. In response, the City Council asked staff to look into allowing an exception for properties with heightened security concerns.
Staff worked with the City’s Police Department and reviewed crime information from the past year for areas near the San Francisquito Creek. While the information showed that crimes and calls for service do occur in this area, they were not significantly higher in the specific residential neighborhood mentioned compared to other areas of the City. The Police Department also confirmed that the City currently does not have any areas identified as having special concerns due to high crime rates, and there are not areas in Palo Alto that they would characterize as “high crime.” While crime data do not support the designation of specific areas as high security risk zones, staff recognize some residents may have heightened perceptions of safety concerns based on local conditions or experiences.
The Edgewood neighborhood does have unique characteristics that could justify different lighting standards including proximity to the creek, lot arrangements, and bordering another jurisdiction. As a result, to implement the Council’s direction, staff have included an exemption in the draft ordinance specific to the Edgewood neighborhood. While the draft ordinance currently exempts this neighborhood from the new outdoor lighting standards, the curfew requirement would still apply to the neighborhood, unless otherwise directed by the City Council.
Measures to Support Compliance
The City does not have sufficient resources to proactively enforce the new outdoor lighting ordinance. While staff will respond to egregious violations as capacity allows, most violations are expected to occur outside of typical Code Enforcement hours (i.e., at night), and staff are already managing a full caseload of other enforcement matters. Additionally, the compliance timelines established in the ordinance, as directed by the City Council, are unlikely to result in full compliance within the specified periods.
Staff remain concerned about establishing regulatory standards that cannot be reliably enforced, as this may lead to unrealistic expectations in the community regarding the extent of compliance that can be achieved.
Recognizing these challenges, the City Council directed staff to explore additional options to support a community-based approach to compliance. The following measures are not part of the ordinance itself but could be implemented after the ordinance is adopted:
Neighbor Letter Template: A letter template modeled on tools used by the City of Brisbane and DarkSky International could allow residents to inform neighbors about the ordinance and encourage voluntary compliance. While this may reduce initial complaints to the City, it relies on voluntary action and may lead to disputes or unprioritized reports.
Educational Materials: Staff will develop outreach materials, including online content, printed handouts, and utility bill inserts, to raise awareness about the new requirements. This approach aims to reduce inadvertent non-compliance through public education but has no direct enforcement effect and depends on public engagement. Affidavit Letter: Staff considered requiring applicants and property owners to sign an affidavit acknowledging awareness of the lighting requirements during the permit process. However, this approach would duplicate information already reviewed as part of plan review and introduce additional regulatory steps to the permitting process, and is therefore not recommended.
These supplemental efforts are intended to promote broader awareness and voluntary compliance in the absence of dedicated enforcement resources.
Exemption for City Facilities
Since this report was first published, staff have updated the ordinance to explicitly exempt lighting for streets, roadways, public walkways, and bikeways. This clarification ensures the City will not be required to modify its existing lighting infrastructure as a result of the ordinance.
An additional exemption authorizes the City Manager to exclude public facilities that operate 24 hours a day, seven days a week when such an exemption is necessary for facility operations or safety.
Together, these changes reflect the need to balance essential City operations and the safety and well-being of employees and the community with the City’s goal of reducing nighttime light pollution and promoting a healthier environment for wildlife.
Additional Minor Changes
To reduce redundancy, the Outdoor Security Lighting requirements previously found under the Special Purpose Lighting section were removed. These requirements largely duplicated the citywide outdoor lighting standards.
POLICY IMPLICATIONS
The Lighting Ordinance Update aligns with the Comprehensive Plan’s Natural Environment Element, which aims to preserve natural resources through sustainable practices and climate adaptation. Policy N-7.5 seeks to minimize light from development, Policy N-1.9 mandates shielding exterior lighting in foothills, and Program N3.3.3 requires the careful design of lighting surrounding natural riparian corridors. The ordinance improves nighttime visibility for wildlife, enhances energy efficiency and supports environmental protection and community health goals.
While not directly related to the Palo Alto Sustainability Climate Action Plan (S/CAP), the ordinance supports the goal of enhancing ecological resilience. It provides better habitats for nocturnal wildlife, aiding environmental conservation. Although not a specific S/CAP goal, the ordinance may reduce electricity usage, as outdoor lighting will have motion sensor controls, thus fostering sustainability and supporting S/CAP objectives.
Under Program 3.2 of the Housing Element, the City must analyze how new regulations impact housing production. The Lighting Ordinance is not expected to significantly affect housing, as it doesn't change density, layout, or height. Minor cost or design modifications may be needed for compliance, but dark sky products and lighting technologies are available.
FISCAL/RESOURCE IMPACT
Staff anticipate a misalignment in the community’s expectations to enforce this ordinance relative to existing code enforcement workload and resources. Except for documented isolated and egregious violations of the ordinance, staff will rely on low-cost supplemental measures such as a letter template that can be used between neighbors and potential educational materials to inform the community about requirements and standards.
STAKEHOLDER ENGAGEMENT
Staff conducted two study sessions, one in February and another in July 2024 through the ARB to provide a forum for community members to express their views and concerns regarding the proposed ordinance. In addition, staff have engaged with representatives from the Santa Clara Valley Audubon Society and Sierra Club Loma Prieta Chapter to solicit their input on the proposed ordinances.
On October 8, 2025, Staff conducted a focused outreach meeting with Palo Alto businesses and presented draft ordinance. A total of 38 participants attended this focused outreach meeting that was held virtually, and the participants included members of the Palo Alto Chamber of Commerce, Stanford University, and businesses/developers of Stanford lands. Several attendees expressed concerns about the requirement to bring all existing lighting up to the new standards, which could require expensive investments to completely redesign lighting plans.
Other members were concerned about safety implications of reducing lighting at commercial facilities that have overnight operations, noting specifically that Federal Occupational Safety and Health Administration (OSHA) workplace regulations would require lighted walkways, for example. The requirement for existing lighting to comply with the new lighting regulations in the ordinance was directed by the City Council at the April 7, 2025, meeting; as a result this requirement remains in the draft ordinance. However, the ordinance does include exceptions for lighting at building entrances, parking areas, walkways, and driveway areas, and safety requirements in Federal or State law (including OSHA regulations) will supersede this ordinance where required. The outreach meeting materials, including the staff presentation and recorded meeting, are available on the project website at www.PaloAlto.gov/OutdoorLighting.
Staff received numerous comment letters from the Santa Clara Valley Bird Alliance (formerly known as the Santa Clara Valley Audubon Society) and Sierra Club Loma Prieta Chapter on various versions of the draft ordinance presented to the ARB and PTC. These comments were considered and incorporated into draft ordinance throughout the process. The latest ordinance reflects many of the suggestions received.
At the time of staff report preparation, staff received one comment letter from a resident of Crescent Park. While supporting responsible outdoor lighting, the resident is opposed to the proposed Lighting ordinance update due to its overly restrictive nature, negative impact on safety, and lack of sufficient community input.
All public comments received for the draft lighting ordinance are in Attachment B.
Future Outreach
PTC recommended to the City Council that further outreach be done at the time of implementation, informing residents of the new regulations; and that regulations for interior commercial lighting be considered in the future. Unless directed otherwise, staff will inform the project’s interested parties about the ordinance adoption and provide a copy for review. Staff will also prepare information to be shared on the City’s website and at the Development Center regarding the new regulations and communicate as appropriate through other City communication channels. The City Council could also consider additional regulations for interior commercial lighting at future priority-setting sessions.
ENVIRONMENTAL REVIEW
The City has reviewed these proposed ordinances in accordance with that authority and criteria set forth in the California Environmental Quality Act. The City, as the lead agency, anticipates that these ordinances will be exempt from CEQA in accordance with CEQA Guidelines Section 15308, which includes actions by regulatory agencies for the protection of the environment.
ATTACHMENTS
Attachment A: Draft Ordinance Updating Lighting Standards (PAMC Section 18.40.250) Attachment B: Examples of Educational Materials and Template Neighbor Letters Attachment C: Public Comments received after the City Council hearing on April 7, 2025 APPROVED BY:
Jonathan Lait, Planning and Development Services Director