Final answer:
The key factor influencing Diurnal temperature range is solar intensity, which affects the Earth's temperature in correlation with its variation. Cloud cover and the elevation of the Sun can also affect temperature variations.
Step-by-step explanation:
The key factor that influences Diurnal temperature range is the variation in solar intensity.
Solar intensity, which is the amount of solar power or energy the sun emits in a given amount of time, has a direct relationship with temperature.
During the day, the amount of sunlight that reaches the Earth influences temperatures, with higher solar intensity leading to higher temperatures.
Cloud cover can also play a role by reflecting some of the solar radiation back into space, reducing heating.
Lastly, the elevation of the Sun also affects diurnal temperature variation as the angle at which sunlight hits the Earth determines how concentrated the heat is over a certain area.
For instance, when the Sun is overhead, the illumination is more concentrated, leading to greater heating compared to when the Sun is near the horizon.