There are
1,685 mi
from Harlingen, TX to Plum, PA
That's the driving distance. It would take 1 day 7 hours to go from Harlingen, Texas to Plum, Pennsylvania.
The flight distance (direct flight from Harlingen, TX to Plum, PA) is 1,426.53 mi.
1,685 mi = 2,711.09 kms