Mayor Zohran Mamdani told New Yorkers to set their air conditioners to 78 degrees during a brutal heat wave, then his own City Hall blasted the AC so hard that temperatures in one room dropped to 54 degrees. The New York Post sent reporters with an infrared thermometer into 20 spots across City Hall and other municipal buildings. Fifteen of those locations registered below the 78-degree threshold the mayor had publicly recommended to millions of residents.

Central Park hit 100 degrees that afternoon, the first time in more than a decade. Roughly 5,000 Con Edison customers in the Bronx lost power. And inside the building where Mamdani governs, the Rotunda sat at a brisk 64 degrees.

The gap between what the mayor asked of ordinary New Yorkers and what his own office delivered is the kind of detail that writes itself. It also captures something broader about how Mamdani's administration operates: announce a grand directive, claim compliance, and leave the public to discover the truth on its own.

What the thermometer found

Post reporters tested temperatures at roughly noon and again around 4:30 p.m. on a Thursday during the ongoing heat wave. At noon, the area near Mamdani's second-floor office, the Rotunda, the Governors' Room, and the City Council chambers all read 77 degrees, one degree below the recommended setting. The mayor's first-floor press office came in at exactly 78.

Then the readings started falling. Shortly after noon, the area outside Mamdani's office dropped to 74 degrees. The Governors' Room matched it. The Rotunda plunged to 64.

By 1:30 p.m., the spot near the first-floor press office, where Mamdani's communications staff and other aides had gathered, read 62 degrees. That is sixteen degrees below the threshold the mayor told New Yorkers to endure.

The coldest reading came from an AC unit in the press radio room: 54 degrees. By that point, Central Park had already crossed 100 degrees two hours earlier, and thousands of Bronx residents were sitting without power at all.

The mayor's public claim

Mamdani had not been shy about the recommendation. On Wednesday, he urged New Yorkers to set their air conditioners to 78 degrees or higher, citing the risk of dangerous Con Edison power outages during the heat wave. He then posted on the official @NYCMayor account on X:

"Our City is doing its part too: maintaining the 78 degrees rule in our buildings, dimming/turning off our lights during peak electricity demand, asking private partners to do the same, and powering down non-essential equipment."

That claim, "maintaining the 78 degrees rule in our buildings", was directly contradicted by the Post's readings the following day. Fifteen of twenty tested locations fell below 78. Several fell far below it.

The contradiction did not escape Republican critics. Fox News reported that Mamdani simultaneously urged residents to cap AC at 78 degrees and warned elderly New Yorkers to stay cool in air-conditioned spaces, instructions that plainly conflict with each other. Social media users seized on the incoherence, with conservative media personality Gina Milan responding: "You just told old people to keep their air at 78. Are you on drugs?"

City Hall's response, after getting caught

Mamdani spokesman Jeremy Edwards told the Post that "the Mayor set the temperature at Gracie Mansion to 78 degrees yesterday afternoon." Edwards also confirmed that City Hall's temperatures were set to the recommended levels late Thursday, after the Post began asking questions.

In other words, the city adjusted its thermostats only after reporters showed up with a thermometer. That sequence is worth lingering on. The mayor publicly declared his buildings were maintaining the 78-degree rule. The buildings were not. And the fix came not from internal compliance but from external embarrassment.

Mamdani's top spokesperson, Joe Calvello, spent much of Thursday posting on X against critics of the 78-degree recommendation. In one reply to Barstool Sports founder Dave Portnoy, Calvello wrote: "This practice of asking New Yorkers to set their AC to 78 degrees dates back to Dear Communist Leader Mayor Rudolph W. Giuliani." The sarcasm was clear. So was the deflection.

It is true that past mayors, Eric Adams, Bill de Blasio, and others, have given similar advice during heat waves. But none of them posted a public claim that city buildings were complying while the Rotunda sat at 64 degrees. The issue is not the recommendation itself. The issue is the claim of compliance that the mayor's own building could not support.

Blocked doors and sweltering hallways

The Post's testing extended beyond City Hall. At the CityStore inside the Manhattan Municipal Building, the temperature registered 64 degrees. In the Dinkins Building, hallways and lobbies sat at 80 degrees, above the recommendation, while elevators hit 89 degrees. Security officers and police stationed in those hallways sat in 80-plus-degree heat without fans.

The Mayor's Office of Climate and Environmental Justice, which sat empty at the time of testing, came in at 81 degrees. The irony needs no elaboration.

Staff at several other municipal buildings, described as offices for sanitation and health, blocked Post reporters from entering when they learned about the temperature-testing project. No stated reason for the refusal was reported. Whatever those buildings' thermostats read, the public will not know.

Meanwhile, Con Edison issued a statement explaining the Bronx outages: "Due to an electric problem in Riverdale, we had to shut off power to some customers temporarily to prevent more extended outages. We're completing repairs as quickly as possible." Those roughly 5,000 customers did not have the luxury of debating whether to set their AC to 78 or 54. They had no power at all.

A pattern, not an incident

The AC episode is a small thing in isolation. But it fits a pattern that has defined Mamdani's tenure. The self-described democratic socialist has drawn repeated criticism for governance that favors grand pronouncements over competent execution.

The Washington Examiner reported that multiple high-profile Republicans, including Vivek Ramaswamy, Arkansas Governor Sarah Huckabee Sanders, and Florida Governor Ron DeSantis, seized on the AC directive as a symbol of socialist governance in practice. "This is what socialism looks like, folks," Ramaswamy posted on X. Sanders added: "Turns out socialism actually isn't free." The criticism landed just days after Mamdani publicly declared that socialism represents the Democratic Party's future, following primary wins for socialist candidates in multiple races.

Mamdani's broader record has supplied no shortage of material. His administration has weighed delaying payments to nonprofits serving the city's most vulnerable residents, raising questions about whether ideological ambition has outpaced basic fiscal management.

On federal matters, the mayor has twice pledged to defy Supreme Court rulings on deportation protections, a posture that puts his administration at odds with constitutional order and invites legal consequences he seems willing to court for political positioning.

And his political operation has reshaped New York's Democratic landscape. Mamdani-backed socialist candidates routed Democratic incumbents in recent primaries, alarming even figures like Attorney General Letitia James. The mayor is building a movement. Whether he can manage a thermostat is a separate question.

The real temperature check

City Council Minority Leader David Carr, a Staten Island Republican, offered the cleanest summary of the episode:

"Maybe the mayor shouldn't tell New Yorkers to sacrifice their comfort if he isn't willing to do the same."

The U.S. Department of Energy suggests keeping thermostats between 75 and 78 degrees over the summer. That is a reasonable range. Asking residents to conserve during a genuine grid emergency is defensible. What is not defensible is posting a public claim that city buildings are complying while your own Rotunda reads 64 degrees and your press room reads 54.

The Governors' Room at City Hall was being prepped with a teleprompter, cameras, and lights for Mamdani's Fourth of July address the following day. Whatever the mayor planned to say about the city he leads, the infrared thermometer had already delivered the more honest reading.

Rules for thee, 54 degrees for me. It is a small hypocrisy, but the small ones tend to tell you the most about how the big ones work.