If the weather is characterized by strong air movement, which phrase would apply?

When strong air movement is described, the most fitting term to use is "windy." Windiness specifically refers to conditions where there is a notable movement of air, which can occur during various weather patterns. This strong movement of air can be a result of differences in air pressure, temperature changes, or storms, all of which lead to observable wind.

Other options such as "rainy," "sunny," and "snowing" describe different weather conditions that may or may not involve significant air movement. While it can be rainy during windy weather, rain itself does not imply strong air movement; it merely indicates precipitation. Similarly, sunny weather typically represents calm conditions, lacking the air movement associated with wind. Snowing might involve some air movement, but it primarily denotes the presence of snowfall rather than the strength of that movement. Thus, "windy" is the most accurate phrase to describe weather characterized by strong air movement.