What factors primarily determine if there will be precipitation?

Precipitation primarily depends on temperature and hygroscopic nuclei. Temperature plays a crucial role because it influences the amount of moisture air can hold; warmer air can contain more moisture than cooler air. When air reaches its dew point—where it is saturated with moisture—condensation occurs, and clouds form.

Hygroscopic nuclei are tiny particles in the atmosphere that attract water vapor, facilitating the condensation process necessary for droplet formation. Without these particles, water vapor struggles to condense into liquid droplets, making precipitation less likely. Essentially, the combination of adequate temperature and the presence of hygroscopic nuclei creates the right conditions for droplets to form and fall as precipitation.

Other factors such as atmospheric pressure, humidity, wind speed, cloud cover, and elevation can influence precipitation patterns but are not as directly responsible as temperature and hygroscopic nuclei. For instance, while humidity is essential for cloud formation and precipitation, it must interact effectively with temperature and nuclei for actual precipitation to occur.