People making huge generalizations off an observation is a pet peeve of mine. My memory tells me having a warm day in February is rather common. But my memory is just as flawed as OP. You know what is less flawed? Data.

I searched for NYC weather data in a downloadable format. I found such at: https://www.ncdc.noaa.gov

I couldn't find central park. But JFK should serve the task. I asked for 1980 to 2022. They gave me 1980 to 2007. 28 years is still a decent set of data.

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Well, in February from 1980 to 2007, 28 years, 14 of those years had a day at or above 58 degrees. That means 50% of February have a 58 degree day. This is completely normal.

Just for fun, the warmest day in February was 71 degrees in 1997. The coldest warmest day was 1986 at 49 degrees.

And no, its not getting more frequent during the data set. Fairly even. Longest strech of years with a 58 or above was 1988 to 1992. Longest stretch without a day at or above 58 was 1999 to 2001