Weather Insider: What is hail and why is it common in the summer?
Hail is a form of frozen precipitation that falls from thunderstorms as clumps of ice. At the core of every thunderstorm is an updraft, or an area of rising warm, moist air. When this warm moist air reaches the colder levels of the atmosphere, the water vapor will condense and form clouds and rain. However, some of the liquid water can form ice. These little pieces of ice can bounce around in the thunderstorm growing larger until it is heavy enough to fall to the ground.
Hail can form at any time of the year, but is typically associated with the spring and summer months. This is because most of the intense storms that produce hail tend to form in the spring and early summer. Here in the Coachella Valley, hail is not very common but is possible with some monsoonal storms.