NEW YORK CITY — Serious crime increased in three-quarters of the city's neighborhoods last month as New York heads into a summer that may be long, hot and violent, DNAinfo New York has learned.

Fifty-seven of the city's 76 NYPD precincts reported spikes in serious crime during a four-week period ending May 24 compared to the previous four weeks, according to NYPD statistics compiled on a new DNAinfo crime mapping system.

The other 19 precincts reported overall crime remained steady or declined during the period, compared to the previous month.

While it has long been police lore that crime rises with warmer weather, the trend is even more disturbing because it is not confined to the two eye-catching categories — murder and shootings — that Mayor Bill de Blasio and police brass have blamed on localized gang activities.

Serious crime includes rape, robbery, assault, burglary, grand larceny and auto theft.

DNAinfo New York's map, which pulled data directly from the NYPD's publicly available CompStat statistics, reveals rising criminal activity across broad swaths of the Big Apple — not just a few trouble spots.

In Brooklyn North, for example, all 10 precincts show increases ranging from 2 percent in Bed-Stuy's 81st Precinct, to 36 percent in Williamsburg's 90th Precinct.

Brooklyn South reported five precincts with declines, including the 60th in Coney Island and the 61st in Sheepshead Bay. But eight showed increases, inlcuding a 35 percent jump in Kensington/ East Flatbush's 70th precinct and a 26 percent jump in Flatbush.

In The Bronx, 10 of 12 precincts reported increases. The 40th Precinct in Hunts Point had a 44 percent spike; the 46th Precinct in Wakefield reported a 38 percent rise; and the 48th Precinct in Fordham and Baychester's 49th Precinct both showed 28 percent increases.

Queens North has eight precincts and seven are up, with only the 108th Precinct in Long Island City recording a decline over the previous four-week period, according to the NYPD stats.

Six of seven precincts in Queens South are also rising, with the 102nd Precinct in Richmond Hill/Kew Gardens leading the way with a 40 percent jump. Only the 100th precinct in Belle Harbor/Rockaway reported a decline.

Two of Staten Island’s four precincts — the 120th in St. George and the 121th in Graniteville — reported increases of 16 percent and 9 percent, respectively. The 122nd precinct in New Dorp reported a 20 percent decline and the 123rd in Tottenville was down 9 percent.

In Manhattan North, eight of 12 precincts reported increases. There was a 100 percent jump in Central Park, a 28 percent rise on the Upper West Side and 27 percent in Hamilton Heights in May versus the previous month.

Harlem, however, showed a 27 percent decline in the 30th Precinct, the borough’s steepest drop.

In Manhattan South, six of 10 precincts reported increases, including the East Village, Chelsea, and Midtown.

Police officials point out that overall crime in the city is down through last Sunday May 31 by 6.6 percent compared to the same period last year. And any increases come off historically low levels not seen here since the early 1960s.

But homicides are up 20 percent this year, with 135 reported murders compared to 113 during the same period last year, according to police data. Shootings are also up 9 percent — 439 this year, compared to 403 in 2014, records show.

Police officials blame the spike in shootings and homicides on weather, gangs and guns. Deputy Commissioner Stephen Davis acknowledged that May "had been a tough month. And last Monday, Chief of Department James O'Neill said "we are struggling with homicides and shootings" and that the NYPD was freeing up 325 officers from desk duty to fight crime.

The department is also lauching its overtime-heavy "All Out" summertime program a month earlier than planned to flood high crime neighborhoods with officers.

But many observers say the increased criminal activity is also linked to the plunge in NYPD stop-and-frisks.

During the high-crime 1990s, NYPD officers were stopping and frisking about 100,000 people annually.

But after Michael Bloomberg became mayor in 2002, the numbers skyrocketed under Police Commissioner Ray Kelly to 685,000 in 2011 until the public and the courts called for a federal police monitor and the creation of an NYPD inspector general.

Ultimately, Mayor Bill de Blasio was elected on a platform of dismantling aggressive policing.

Since then, the number of stop-and-frisks plunged to just 38,051 last year and to 7,135 through March this year, officials said.

“Since the city has ceased stop-and-frisks, the NYPD needs to replace it with some other type of aggressive enforcement that targets the right people,” one former top police official observed.

But that may not be enough given the swing in crime. And compounding matters is the sense that New York's Finest have “taken a step back” fearing that “their every action is deemed to be overly aggressive,” the ex police official observed.

So that leaves the NYPD trying to increase its street presence to deter crimes. But with its thin ranks and the need to man specialized units to confront possible terrorist activities, the NYPD will be hard pressed to find the resources.

De Blasio has turned down calls from the City Council and Police Commissioner Bill Bratton to hire an additional 1,000 officers.

“So what you have are criminals thinking they have the upper hand while, conversely, the police are getting less aggressive,” the former top police strategist said.

“[Police Commissioner] Bill Bratton is a smart guy. He should be able to figure it out. If he can't, crime may finally begin to rise.”

Mayor Bill de Blasio said Tuesday that he was confident the NYPD would "turn the tide" on the spike in homicides and shootings.