The heat begins to scorch them.
Dark Clouds.
If the sun sets in dark, heavy clouds, expect rain next day.
If at sunrise there are many dark clouds seen in the west and remain there, rain will fall on that day.
Double Setting.
Sun setting double indicates much rain. Red sun indicates fair weather. Orange sun usually foul weather. Mock suns in winter are usually followed by intense cold.
Dull Color.
When the sun appears a pale or dull color, expect rain.
Drawing Water.
Rays of the sun appearing in a cloud forebode rain. This phenomenon is, in fact, caused by the image of the sun being reflected in an intervening cloud, the reflected image radiating in the cloud. It is noticed by Aristotle.