The science of the study of weather is called meteorology. Meteorology is the study of the changes in temperature, air pressure, moisture, and wind direction in the lowest part of the atmosphere in which most of the observed weather phenomena occur. Meteorologists investigate these day-by-day variations in the weather.
Weather phenomena are governed by a set of physical and chemical processes which are determined by simple mathematical relationships. The way these processes interact however, creates a much more complex system, which is why the weather can be so unpredictable and hard to forecast. Meteorology combines the disciplines of mathematics, physics, chemistry and geography to try to simplify the understanding of an inherently complex atmospheric system.