Locality has considerable to do with what the fog indicates. As a rule,
where you have fog, there is not much wind, and as a result it does not
indicate stormy weather, unless the fog becomes heavy with overhanging
sky, then it is apt to turn into rain, but a heavy fog with a light sky
indicates fine weather. A fog in the morning generally indicates a fair
day. A rising fog is a good indication for fair weather.
[Illustration:
_Courtesy Julien Friez & Sons, Baltimore, Md._
Fig. 34
]
[Illustration:
Fig. 35
]
Dew is a pretty good sign of fine weather. When you can see and hear
with remarkable clearness, and everything is calm and still, it is a
pretty infallible sign that cold weather is due.
Frost may be looked for on clear, calm, cloudless nights, when the
ground is apt to be cooler than the air.