Where smoking is banned
New York City prohibits smoking in a notably broad range of public spaces: all indoor workplaces, restaurants and bars (since 2003), parks, beaches, pedestrian plazas (including Times Square), outdoor dining areas, sports stadiums, and public transit vehicles and stations. The list has been expanding consistently for two decades.
Cannabis
Cannabis was legalised for recreational use in New York State in 2021. However, the rules around where you can consume it largely mirror tobacco rules — smoking cannabis in the same places tobacco is banned (parks, beaches, outdoor dining areas, building entrances) is also prohibited. Consumption in licensed cannabis lounges is permitted where those businesses exist. Do not smoke cannabis in hotel rooms — the cleaning fees are substantial and the hotel rules are independent of state law.
Vaping
E-cigarettes and vaping devices are subject to the same public space restrictions as tobacco in New York City. Vaping in a park, on a beach, or in a restaurant is not permitted.
Enforcement
Enforcement is real but uneven — in tourist-heavy areas you'll frequently see people smoking in prohibited spaces without consequence, and in others the rules are actively enforced. The existence of regulations should be taken at face value; the likelihood of being fined depends heavily on context.