Based on the 1991 - 2022 US Climate Normals published by NOAA, the average day for the last spring freeze in Central Park, New York City is April 1 to 15th. In our tri-state metro area, the average date can be as late as April 30th. 

Bear in mind that these dates are averages and it is safer to err on the side of caution when planting. The actual experienced last frost date (or first frost-free date) can vary by several weeks in any given year. Always consult your local long-range weather forecast before making planting decisions and keep in mind that:

• Some plants should not go outside even when the risk of frost is past.
• We can get a late frost in any year. 
• Any location can have a micro-climate that is different from the surrounding region.  
• Soil temperature does not change as quickly as air temperature and many plants are comfortable outdoors only when soil temperature and night temperatures have warmed up. 

The National Weather Service has some useful resources that predict climate factors with an extended outlook. The forecasts are very general but can be useful in informing gardening decisions.

See also When should I expect the First fall Frost in the New York City Area?