Thanks for your question about your cedar trees. The pictures certainly are helpful to see the pattern of the disease, but it would be even more helpful if you can take some close-up pictures of the foliage of one or more of the trees' needles to determine whether there might be a fungus, or whether the browning is occurring due to drought or other weather stress.
Here's a link to a general Extension article on the subject, which might be helpful to you. If you'd like to submit more information, I'll try to be more specific. Thanks!
Thank you for your additional photos. As the cedar flagging article I referred you to indicated, there appears to be a pattern of the old growth turning brown, while most of the new growth appears healthy (or at least healthier!) There is really no treatment nor cure for this, absent some pathogen (bacteria or fungus) that isn't apparent from any of the pictures. Your trees are going to have far less foliage in the future, but the only help you can give them, as the article recommends, is more summer watering and no disruption of the plants' roots. Good luck!