It took three months and a 10-person “snow team” to finally set the record straight about January’s blizzard — that it was, in fact, the biggest in the city’s history.

The National Weather Service said on Thursday it changed the Central Park snow total from Winter Storm Jonas to 27.5 inches — half an inch more than the 2006 record of 26.9 and .7 inches above the initial measurement 26.8 on Jan. 23.

A day after the storm, The Post quizzed agency officials about the accuracy of the measurement and they vehemently stood by the findings.

“It fell just short of the record and we have full confidence in the measurements we’re getting from Central Park,” meteorologist Faye Barthold insisted at the time.

But behind the scenes, questions swirled about the numbers — and the NWS assembled a crack team of scientists that included meteorologists, a Rutgers University professor and even a member of the Federal Aviation Administration.

“You see an amount that’s very high and wonder, is that a record?” explained Andrew Horvitz, one of seven meteorologists who worked on the investigation.

The National Oceanic and Atmospheric Administration blamed the mistake on a “communication issue” between the NWS and the Central Park Conservancy, which took over snowfall-tracking duties this year.

“During this storm, one of the measurements was not written down properly at our forecast office when it was conveyed over the phone by the observer at the Conservancy,” said NOAA spokeswoman Susan Buchanan. That measurement was the blockbuster 27.5-inch total.

When asked why it took three months to adjust the count, Buchanan said, “The process takes time, especially since the team members were working on this effort simultaneous to other responsibilities.”

The snow team also found that Newark airport has been improperly measuring accumulations since 1996, tracking hourly instead of every six hours.

“You’re going to get inflated totals that way. We want to be consistent and representative of the actual amount that fell,” Horvitz said.

The airport’s 28.1-inch total from Jonas will be revised downward.

“Snow measurements are extremely difficult to take because precipitation is inherently variable, a problem compounded by strong winds and compaction during a long duration event,” Louis Uccellini, director of the NWS, said in a statement.