The country is fairly large, with diverse conditions. Any region in
particular that your family is interested in?
There are some regions with more reliable summer weather than
others. The Southwestern states would very likely provide sunny days
for a 1-week trip. Some other parts have great places to fly but have
a good possibility of "couldn't even get in a full 18 holes of golf
due to the rain" (stolen from Ray's 15M Nationals post) even in
summer.
Jim