The ideal “look” for the American flag when being flown is a full appearance of the entire flag, extended out from the flagpole. On days with no wind whatsoever, obviously this isn’t going to be achieved.
Here’s a little interesting information about how wind affects our flag, using what is known as the Beaufort Scale (Bft.) for wind speed.
In addition to actual wind speed, the type of flag – i.e., what it’s made out of – will also have an affect on what wind does to it. A light nylon flag, for example, will be more affected by wind than one made of heavy sewn cotton.
At a wind speed of zero, naturally, no flag will begin to open up. At one to four mph (1 Bft.), a typical flag will open and close periodically with part of its top section draped over the bottom.
In winds of five to seven mph (2 Bft.), the flag will be extended most of the time and exhibit deep waves that will flip the corners back and forth.
Eight to 11 mph is the optimal wind speed to fully unfurl a flag and exhibit it the way we all think of it – fully open.
In very strong winds, flags can be damaged, so it’s best to bring down a flag in these conditions.