The 2026 Urban20 (U20) Mayors Summit, co-chaired by New York City and Los Angeles, will be held in New York from Sept. 19 to 21. Twenty-five mayors and deputy-mayor-level officials from 34 cities in G20 countries will discuss housing costs, climate and immigration, and adopt a joint communiqué on the 21st. Climate Week NYC follows from Sept. 20 to 27.
New York City Mayor Zohran Mamdani opened the 2026 Urban20 (U20) Mayors Summit on Sept. 19, welcoming mayors from U.S. and international cities to New York. The three-day summit runs through the 21st, with 25 mayors and deputy mayors and senior officials from 34 G20 cities attending. New York City and Los Angeles are co-chairs this year, and the summit is organized by the C40 Cities Climate Leadership Group (C40) and United Cities and Local Governments (UCLG).
The mayors of Atlanta, Chicago, Denver, Miami, Phoenix, San Diego and Seattle will attend from the U.S., joined by city representatives from Canada, Europe, Africa, Latin America and Asia. The mayors will share steps their cities have taken on building affordable housing, protecting tenants, lowering energy bills, supporting immigrants, creating jobs, and responding to climate disasters such as heat waves and floods. The summit will conclude on Sunday, the 21st, with the adoption of a joint communiqué setting out an agenda for shared city action, and representatives of national governments and international organizations such as the United Nations are expected to respond.
"Working families around the world are under pressure from rents rising faster than wages, energy bills that spike every summer, and heat waves that make apartments dangerous," Mayor Mamdani said. "In an era of division and retreat, cities are choosing to work together." Co-chair Los Angeles Mayor Karen Bass said cities are on the front lines of building affordable housing, responding to climate change and protecting immigrant communities, and that by sharing one another's successes they can deliver results faster.
Climate Week NYC Begins on the 20th
The U20 summit kicks off Climate Week NYC, which runs from Sept. 20 to 27. During Climate Week, C40 mayors will join government, business and civil society leaders to address issues including responses to heat waves and extreme weather, improving air quality and sustainable housing. City Hall said the discussions will carry over to the 31st UN Climate Change Conference of the Parties (COP31), to be held later this year. Information about the summit is available at urban20.org.