Sex crimes are soaring in the city, with an especially frightening spike taking place during the past few weeks, The Post has learned.

Misdemeanor sexual assaults as of Sunday night this year increased by 20 percent over the same period in 2014, from 1,003 to 1,203.

But they shot up 75 percent for the week ending Sunday compared to the same week last year — from 45 to 79.

And they were also up 45 percent for the month of May compared to May 2014, climbing to 284 incidents from 196.

Such misdemeanors include forcible touching, sexual misconduct, second- and third-degree sexual abuse and third-degree patronizing a prostitute. They include crimes such as groping on subways and buses.

Felony sex crimes — such as forcible rape, predatory sexual assault against a child, sex trafficking and sodomy — were also up across the board. Year to date, such felonies are up 8 percent, from 502 to 540.

For the week ending Sunday, they rose from 25 last year to 31 this year — a 24 percent jump.

And for the month of May compared with May 2014, they rose 22 percent, from 92 to 112.

Some of the biggest jumps in misdemeanor assaults came in Manhattan. In the Manhattan South Precinct, weekly numbers showed a 200 percent rise, from 4 misdemeanors to 12, while the Manhattan North Precinct saw weekly numbers rise 366 percent, from 3 to 14.

Linda Fairstein, head of the sex crimes unit for the Manhattan DA’s Office from 1976 to 2002, was shocked by the numbers.

“That is quite stunning to me in the worst way,” she said. “Traditionally, there is an increase in the number of sex crimes in warm weather.”

An NYPD spokesman said, “The recent increase in complaints may be in part attributed to expanded outreach and awareness efforts undertaken to encourage victims to report these crimes.”

Additional reporting by Daniel Prendergast