Rain is a common meteorological phenomenon that occurs when water vapor in the air condenses and falls to the ground as liquid precipitation. While it is often associated with clouds and overcast skies, it is possible for it to rain even when the sun is shining.

One reason why it can rain when the sun is out is because of a phenomenon known as virga. Virga is a term used to describe rain or other forms of precipitation that evaporate before reaching the ground. This can occur when there is a layer of dry air above the ground that causes the precipitation to evaporate before it reaches the surface.

Virga can occur in a variety of weather conditions, including when the sun is shining. It is most common in arid or semi-arid regions where there is a high amount of evaporation due to low humidity and high temperatures.

Another reason why it can rain when the sun is out is because of thunderstorms. Thunderstorms are intense storms that are characterized by lightning, thunder, and heavy rain. They can occur at any time of day, including when the sun is shining, and are often accompanied by dark clouds.

Thunderstorms can form when there is a significant temperature difference between the ground and the atmosphere, causing unstable air masses to rise. As the air masses rise, they cool and the moisture in the air condenses, forming clouds and precipitation.

It is worth noting that rain is not the only type of precipitation that can occur when the sun is shining. Other forms of precipitation, such as snow, sleet, and hail, can also occur in sunny weather conditions.

In conclusion, it is possible for it to rain when the sun is out due to phenomena such as virga and thunderstorms. Virga is a type of precipitation that evaporates before reaching the ground, while thunderstorms are intense storms characterized by lightning, thunder, and heavy rain. Both of these phenomena can occur at any time of day and are not dependent on the presence of clouds or overcast skies.