The rise in temperature immediately after rain is often attributed to a meteorological phenomenon called "the rain shadow effect" or "evaporative cooling."
When rain occurs, it is typically associated with the presence of clouds and precipitation. These clouds act as a barrier to sunlight, preventing direct solar radiation from reaching the surface. As a result, the surface experiences reduced solar heating during rainy periods.
Once the rain stops and the clouds begin to dissipate, several factors contribute to the rise in temperature:
Increased solar radiation: As the clouds disperse, sunlight is no longer obstructed, and the surface receives direct solar radiation again. This influx of solar energy leads to an increase in temperature.
Evaporation: After rain, there is an increase in moisture on the ground, such as water droplets on vegetation and wet surfaces. The heat energy from the sun causes the moisture to evaporate, transforming it from a liquid to a gaseous state. This process requires energy, and the heat is drawn from the surrounding environment, causing a localized cooling effect. However, this cooling effect is often short-lived, and once the evaporation process is complete, the temperature starts to rise again.
Sensible heat transfer: The presence of moisture in the air after rain can also influence temperature. Moist air has a higher heat capacity than dry air, which means it can absorb and store more heat energy. As the moisture in the air evaporates, it absorbs heat from the surroundings, including the ground and the atmosphere. This heat transfer contributes to a temporary cooling effect. However, as the moisture content decreases and the air becomes drier, the sensible heat transfer diminishes, and the temperature begins to increase.
It's important to note that the magnitude and duration of the temperature rise after rain can vary depending on local weather conditions, such as humidity, cloud cover, and the intensity of solar radiation. Additionally, other factors like wind patterns and thermal properties of the surface can also influence the post-rain temperature changes.