According to flightaware.com, 138 departing flights and 131 arriving flights were cancelled at Newark Saturday for a total of 269. That is about 28% of their daily departing flights and 27% of their daily arrivals.
In addition, 28 flights were cancelled into and out of JFK and 27 at LaGuardia. Approximately 800 flights were cancelled across the country.
Newark had 303 flights cancelled on Friday, and 724 on Thursday, the day of the last snowstorm.