What natural phenomenon causes the amount of daily insolation to vary at specific locations on Earth?

The amount of daily insolation, or incoming solar radiation, at specific locations on Earth varies significantly due to the seasons. This variation occurs because of the tilt of the Earth's axis relative to its orbit around the sun, which causes different regions to receive varying amounts of sunlight throughout the year.

During summer months, for instance, the hemisphere tilted toward the sun experiences longer days and more direct sunlight, leading to higher insolation. Conversely, during winter months, that same hemisphere is tilted away from the sun, resulting in shorter days and more oblique sunlight, which reduces insolation. This seasonal variation is a crucial factor in determining climate and environmental patterns across different regions, influencing everything from temperature to vegetation growth.

While altitude, latitude, and ocean currents all play significant roles in climate and weather patterns, they do not account for the regular, annual changes in solar radiation that occur due to the Earth's axial tilt and its orbit around the sun.