WHAT FOG AND DEW INDICATE
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.
Courtesy Julien Friez & Sons, Baltimore, Md.
Fig. 34
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.