That’s some cold comfort.

Mayor de Blasio defended ­NYCHA on Tuesday after more than 10,000 residents were hit with heat and hot-water outages on the chilliest day of the year — by claiming the issues were fixed “fast” in nine hours.

“That’s even faster than the number we told you about a month or more ago when we were saying 11 hours was our average,” Hizzoner told reporters during a press conference at Kings County Hospital.

“It’s now down to nine hours in these cases,” he said. “That is a very fast turnaround when there’s an outage, and thankfully the buildings do retain heat pretty well, so people hopefully had very limited impact from such a brief outage.”

De Blasio was responding to local Department of Housing and Urban Development chief Lynne Patton, who blasted NYCHA in an all-caps tweet after the agency celebrated its performance Monday by noting that it had cut the average outage from 36 hours to 10 since last winter.

“WITH ALL DUE RESPECT, PEOPLE SHOULD NOT BE GRATEFUL BECAUSE THEIR HEAT & HOT WATER WAS TURNED BACK ON FASTER THAN BEFORE,” Patton tweeted. “THESE ARE BASIC HUMAN CONDITIONS & EXPECTATIONS FOR ALL AMERICANS. I DON’T CARE IF I’M NOT SUPPOSED TO BE TWEETING DURING THE SHUTDOWN. FIX IT, @NYCHA!!!”

De Blasio said his response to Patton’s point was “amen” — but also that he wanted to share some “facts.”

The mayor’s “facts” included that four housing developments suffered outages “Sunday evening into Monday” — even though six complexes reported a lack of heat throughout Monday, when temperatures remained frigid, according to NYHCA records.

He also noted that “over 3,000” calls about heat being out at private properties were made to 311 Monday — while arguing “public-housing residents deserve the same exact lifestyle and support that people in private housing deserve.

“If we had 3,000 buildings in New York City with heat out yesterday that were private buildings, we had four NYCHA developments with a problem — they were resolved on average in nine hours, that is clearly progress,” de Blasio said.

As the mayor was defending his administration Tuesday, heat and hot-water outages were reported at The Bronx’s Castle Hill and Gun Hill houses and at the Williamsburg Houses in Brooklyn.

At Castle Hill, shivering residents ripped the mayor for his comments — and told The Post the amenities had actually been out for days, even though it only showed up on NYCHA’s “outage” Web site Tuesday.

“We haven’t had heat for like a week,” said Shakeim Lango, 21.

Lango’s mother said she had sent her other son, who has asthma, to stay with an aunt for the past week due to the cold.

Another mom in the development said she was on the way to the hospital Tuesday because her baby’s asthma was flaring up in the arctic weather.

“I have to take the baby to the emergency room now!” Laura Gonzalez said as her family left their apartment. “She’s coughing and she can’t breathe. [De Blasio] has to worry about people having heat in their apartments in this weather.”

Greg Johnson, 29, had to keep his 4-year-old son Easton home Tuesday because the boy got sick. He said the family couldn’t even use portable heaters because they kept blowing the power out. They had been using their oven to heat the apartment.

“If we the adults can’t deal with the cold, imagine what it’s like for the kids,” he said. “They’re sleeping with sweaters and jackets on.”

His mother, Carmella, was also worried about having to go to the ER for her own asthma.

“If my chest continues to tighten I would have to get relief for that at the hospital,” said Carmella Johnson, 48.

NYCHA said the outage at Castle Hill was caused by low pressure and that it was fixed by Tuesday evening — but the Johnsons said they still had no heat.

The cold snap comes after a crisis last winter when more than 80 percent of NYCHA residents were hit with heat or hot-water outages.

The mayor in October hyped a plan to expedite boiler repairs and replacements — but advocates say he was patting himself on the back too soon.

“Despite the Mayor’s ‘Mission Accomplished’ announcement last October touting improvements to boiler systems, it’s abundantly clear, especially over the last few days, that NYCHA still has much work left to do,” said Judith Goldiner, attorney-in-charge at the Legal Aid Society’s Civil Law Reform Unit.

Council Speaker Corey Johnson called the situation “inhumane.”

Additional reporting by Yoav Gonen