"Red sky at night, sailor's delight. Red sky at morning, sailors take warning." A red sunset is probably caused by dust particles suspended in the air, which signifies a dry tomorrow. If it were rainy, the dust particles have been knocked down to the ground. On the other hand, the sky is the red in the morning, then that same dry, dusty air is moving towards the east, away from you. Most likely, moist, cloudy air is blowing in the from the west and pushing the dry air away,
"If smoke goes high, no rain comes by; if smoke hangs low, watch out for a blow." If you can see the smoke from a fire going high up into the air, then there is no wind. The air is probably relatively stable and you do not have to worry about any inclement weather blowing in. However, if your smoke isn't rising very high, it may be due to low air pressure, which prevents the smoke from rising and is also a good indicator of inclement weather to come.
"When the dew is on the grass, rain will never come to pass; when grass is dry at morning light, look for rain before the night." Dew occurs because the moisture in the air condenses on the cool leaves and blade of grass, leaving a residue of moisture, which happens generally during nights where the sky is clear and there is lots of atmospheric pressure. However, if there is no dew, it is probably because the night was cloudy and the grass did not cool down enough for dew to form.
There are dozens, probably hundreds of these little tidbits of folk wisdom out there. While they seem at first glance to be based on pure superstition, it is surprising how many of these sayings are based on solid scientific fact. By learning them, understanding the meteorology behind them, and applying them, you too can develop the uncanny nose for the weather that veteran outdoors people often display.