There are
1,554 mi
from Harlingen, TX to Rialto, CA
That's the driving distance. It would take 1 day 2 hours to go from Harlingen, Texas to Rialto, California.
The flight distance (direct flight from Harlingen, TX to Rialto, CA) is 1,293.42 mi.
1,554 mi = 2,500.54 kms