I'm in a climate very much like yours (Sierra Nevada foothills) where summer days are hot, summer nights are cool, and we can still get downright cold in the winter. But most of the year is fairly dry.
I have my hens in an A-frame coop with the coop on the top of the A and the run underneath. Having the coop up top makes it easier to collect eggs, fill food / water, clean the coop. Having the run down below shades the birds in the summer and keeps the run covered from any snow in the winter. But my coop does not have a window.
On the top part of the A frame where the coop is, one long side opens up (1/2 sheet of siding or plywood) to take care of birds. The other side of the coop A has wire and the side is hinged so I can raise it up for ventilation of the coop in the summer when it gets so hot. My girls also have free run of the pasture when supervised (think hawks, coyotes, skunks).
Our hens like to be let out at dawn or they make a lot of ruckus. Also, they tend to push and shove each other around in the coop and inevitably someone ends up laying an egg outside the nest box and then another comes along and steps on the egg.
I tend to put my hens back in the coop every night, even in the summer due to predators. As said, unless your run is bullet-proof to predators, better to be safe than sorry. When I fist acquired the chickens it took them about 2 weeks to figure out going back to the coop at night. So after a chicken hunt in the dark on the first night, we only let them out into the run for a few weeks until they were always going back to roost in the coop at dark. After that we could let them have the run of the pasture and yard (if someone is home to keep a look out for predators) and they would automatically end up in the coop by dark. Then we just go out and pull on the rope that lifts the gangplank up so they can't get out of the upper coop.
