On July 12, 2022, the Madison City Council approved a new Exterior Lighting Ordinance (replacing the 2017 ordinance). This new Ordinance puts limits on the brightness of residential lighting and reduces permitted brightness of unshielded light fixtures to 500 lumens (= to a 40 watt bulb). Further, the Council voted to commit to the principles of responsible outdoor lighting as defined by the Illuminating Engineering Society and the
International Dark Sky Association, both dedicated to reducing light pollution and preventing “light trespass”.
You can read a press account of the new ordinance
here. The language of the ordinance has not been published on the City of Madison's website yet.