The red color in a morning sky is also caused by sun shining through dust particles, but the dust is being pushed out by an approaching low pressure system that is bringing in moisture. This particular weather lore goes back to biblical times. Depending on where it is, a rainbow can tell you about impending weather. A morning rainbow in the western sky indicates approaching rain, while a rainbow at sunset indicates that the rain is leaving and fair weather is on the way. A bright, clear moon means wet weather is on the way.
Low pressure clears dust out of the air ahead of it.
The particle-free air makes the moon appear closer to the earth and more sharply focused. A halo or ring around the moon also indicates rain. The halo is caused by light shining through cirrostratus clouds, which are an indication of a warm front with lots of moisture getting ready to move through. Reading cloud formations is an accurate way to predict the weather. Cumulonimbus clouds forming early in the day and increasing in size throughout the day, increase the chances of severe weather.