Rising pressure usually means fair weather is coming, falling pressure usually means storms approaching. Cooler air is heavier, warmer air is lighter. Ice crystals fall from cold clouds. In warm weather they melt into raindrops, in cold weather they stay frozen and we get snow. The measure of how hot or cold the air is.
Sunlight is called ultra-violet light.
The never-ending cycle of evaporation, condensation and precipitation that brings us rain and storms. One class did think of something.