There are
1,970 mi
from Harlingen, TX to San Mateo, CA
That's the driving distance. It would take 1 day 10 hours to go from Harlingen, Texas to San Mateo, California.
The flight distance (direct flight from Harlingen, TX to San Mateo, CA) is 1,637.62 mi.
1,970 mi = 3,170.25 kms