Frontal precipitation occurs when warm and cold air masses converge, resulting in the warmer air rising and cooling, which ultimately leads to rainfall.

This type of precipitation is specifically associated with the boundaries, known as fronts, between different air masses. Air masses can be classified as either warm or cold, each possessing different densities. When a warm air mass meets a cold air mass, the less dense warm air is forced to ascend above the denser cold air. As this warm air rises, it cools, and its capacity to hold moisture diminishes. This decrease in moisture-holding capacity results in the condensation of water vapor in the atmosphere, leading to cloud formation. If the condensation process continues, the water droplets within the clouds increase in size and eventually fall to the ground as precipitation.

There are two primary types of fronts that can result in frontal precipitation: warm fronts and cold fronts. In the case of a warm front, the advancing warm air mass rises over the retreating cold air mass. The ascent of the warm air occurs gradually, which typically results in widespread and steady precipitation over a large area. Conversely, in a cold front, the advancing cold air mass pushes beneath the retreating warm air mass, forcing the warm air to rise rapidly. This rapid ascent can lead to the formation of intense and short-lived precipitation.

Frontal precipitation is prevalent in mid-latitude regions, where warm tropical air masses interact with cold polar air masses. For instance, in the United Kingdom, particularly in the western regions, warm, moist air from the Atlantic Ocean frequently meets colder air over land. The occurrence of frontal precipitation can give rise to various weather phenomena, including rain, snow, sleet, or freezing rain, depending on the temperature profile of the atmosphere at the time.