There are
1,037 mi
from Longmont, CO to Montebello, CA
That's the driving distance. It would take 18 hours 16 mins to go from Longmont, Colorado to Montebello, California.
The flight distance (direct flight from Longmont, CO to Montebello, CA) is 832.31 mi.
1,037 mi = 1.61 kms