Mamdani tells New Yorkers to set ACs to 78 degrees amid heat wave

Zohran Mamdani urged New Yorkers to set their air conditioners to 78 degrees as the city faced a dangerous early-July heat wave and rising electricity demand.

He also told residents to turn off lights and electronics they were not using and unplug what they could. According to the reporting available on the guidance, city buildings would follow the same 78-degree setting and would dim or turn off lights during peak electricity demand.

The recommendation came as temperatures climbed across New York and much of the Northeast ahead of the Fourth of July holiday. The National Weather Service had issued extreme heat warnings across New York and neighboring areas, with forecasts calling for highs in the upper 90s and some places potentially topping 100 degrees.

AP reported that New York City had more than 200 teams of government workers and volunteers checking on homeless people and directing them indoors, while hundreds of cooling centers were available for residents seeking relief from the heat.

Heat response and public safety

The city’s message was not just about conservation. It was also framed as a public-safety response to a stretch of extreme heat that posed a particular risk to seniors, people without reliable air conditioning, outdoor workers and others vulnerable to heat-related illness.

Cooling centers were part of that broader response. AP said the city had mobilized emergency outreach, with workers and volunteers checking on people in need and helping direct them to indoor relief.

Why the city is urging conservation

The logic behind the 78-degree guidance is tied to grid strain. When temperatures rise sharply, air conditioning demand can spike at the same time that the city is trying to avoid unnecessary power use.

That approach also aligns with longstanding federal energy guidance. The U.S. Department of Energy says raising summer thermostat settings can save energy and notes that setting the thermostat colder does not cool a home faster.

Chronology of the story

AP published regional heat-wave coverage on July 1, describing the emergency response in New York and nearby cities and noting cooling centers and advice for residents to stay cool indoors.

Later that day, the New York Post reported on the broader city heat response. It then published the specific report on Mamdani telling New Yorkers to set their ACs to 78 degrees at 2026-07-02T03:59:54Z.

That makes the specific thermostat instruction the core news peg, while the heat wave itself remains the larger unfolding emergency around it.

What to watch next

The immediate questions are whether City Hall or New York City Emergency Management issues a direct statement updating the guidance, whether grid operators report any significant strain, and whether the city sees heavier use of cooling centers as the holiday heat continues.

It is also unclear whether critics or other officials will push back on the 78-degree recommendation or endorse it as a practical conservation measure. Any report on outages, expanded emergency outreach or changes to the guidance would materially affect the public-safety picture.