There are
2,949 mi
from San Mateo, CA to Hempstead, NY
That's the driving distance. It would take 2 days 4 hours to go from San Mateo, California to Hempstead, New York.
The flight distance (direct flight from San Mateo, CA to Hempstead, NY) is 2,585.93 mi.
2,949 mi = 3.22 kms