New York City’s heating season, which began October 1 and runs through May 31, requires building owners across the five boroughs to keep apartments above set minimum temperatures. The rules, published by the New York City Department of Housing Preservation and Development, tie the requirement to the time of day and the outdoor temperature, and tenants without heat can file a complaint with 311.

During the day, between 6 a.m. and 10 p.m., a landlord must keep the inside temperature at 68 degrees Fahrenheit or higher whenever the outdoor temperature falls below 55 degrees. At night, between 10 p.m. and 6 a.m., the inside temperature must be at least 62 degrees, regardless of the temperature outside. Hot water is a separate, year-round obligation: it must be available all 365 days at a minimum of 120 degrees.

Because the daytime rule depends on the weather, an HPD inspector records the outdoor temperature at the time of any inspection, and a daytime heat violation can only be issued when that reading is below 55 degrees.