Hello,

This appears to be winter burn on your cedars. If the damage is on the south to west sides, or the prevailing windward sides in your location, these are the sides typically damaged by wind and sun during the winter. The remaining part of the hedge may have received some protection by the building or other structures that shielded it enough from the elements. If the landscape is sloping that direction, the lower section also received more water.

Here is what you can do:

 Clip about 1/2 inch of the foliage to remove some of the dead material. Be sure all the shrubs’ root zones in the hedge are kept moist 12 inches down, until the ground freezes this fall. A lawn sprinkler is not enough. Trees and shrubs need to go into winter fully hydrated. Do not prune later than July so as not to stimulate growth late in the season that may not survive winter. 

Consider placing a temporary windbreak of burlap or other shading material along the west and south sides ( or whichever side get the prevailing winds) of these shrubs in late fall and remove in the following spring when severe weather subsides. Here is a reference describing these techniques:

https://www.extension.umn.edu/garden/yard-garden/trees-shrubs/protecting-from-winter-damage/

http://msue.anr.msu.edu/news/keep_garden_soils_moist_during_a_drought

I hope this is helpful. Thanks for using our service.