During the 1800's they obviously didn't have the technology to Forecast the weather. So instead they used various methods in doing so:
1) When standing on high ground and the horizon is unobstructed from all quarters, if the sky is absolutely cloudless, look for a storm within forty eight hours.
2) If it starts to rain after seven o'clock in the morning it will continue to do so all day, and very often it is the indication of a three day down pour.
3) When it is raining and it brightens and darkens alternately you can count on an all rainy day with a chance of clearing at sundown.
4) When the rain begins to cease and the clouds are still massed in heavy blankets one sure sign of clear weather is the patch of blue sky that shows through the rift large enough to make a pair of sailor's breeches.
5) A foggy morning is usually the forerunner of a clear afternoon.
6) A thunderstorm in winter is always followed by clear cold weather. Does not mean the winter is breaking.
7) A red or coopered color sun or moon indicates great heat, A silvery moon denotes clear, cool weather.
8) The old Indian sign of a dry month was when the ends of the new moon were nearly horizontal and one of them resembled a hook on which the Indian could hang his powder horn.
Red in the morning the sailors warning,
Red at night the sailors delight.
When you can see a mackerel sky,
Twill not be many hours dry.
When the seagulls inland fly,
Know ye that a storm is nigh.
A ring around the moon,
Means a storm is coming soon.
When it rains before seven,
Twill clear before eleven.
Thank you for reading my post hope you enjoyed it :D