What is the best time of year to install a barn owl box?

Since barn owls in most areas of North America begin nesting anywhere from January through April, the easiest answer is to get the boxes installed between December and early March. We have installed boxes in March in California that received high occupancy by April. But the fact is that the best time to put up a box is when you have time. No matter what time of year, barn owls will begin to see the box and become accustomed to it prior to breeding season.