There are
2,915 mi
from Walnut Creek, CA to Hempstead, NY
That's the driving distance. It would take 2 days 3 hours to go from Walnut Creek, California to Hempstead, New York.
The flight distance (direct flight from Walnut Creek, CA to Hempstead, NY) is 2,564.37 mi.
2,915 mi = 4,690.70 kms