Some of great-grandpappy's natural weather signs were accurate. You've probably noticed that frantic feeding activity of birds often presages a storm, especially in winter. Great-grandpappy's belief that highflying birds meant good weather in the offing also has some truth in it. Old-time weather watchers observed insects, birds and even farm animals to get a handle on coming changes. Dry weather followed a heavy dew.
Flies bite harder and are more persistent on approaching storms.
Broken spider webs, stormy weather in a day or two.