When these clouds suddenly appear in the sky on a clear summer day, they
indicate wet weather. Especially if the weather ends turn upward, which
means that the clouds are coming down. When moisture in the form of
little drops cling to vegetation, it is a pretty good indication that
there is apt to be more rain.
When the sky assumes the appearance of a gray mass and the sun is
observed shining through, it is a pretty good indication that it will
rain before night.
When overhead clouds are thick and grayish and the lower surface of them
is lumpy, this is an indication of rain.
Whirlwinds of dust are also indications of rain.