What is the definition of 'diurnal range'?

The definition of 'diurnal range' specifically refers to the difference between daytime and night-time temperatures. This measurement captures how much temperatures fluctuate from day to night, reflecting the variations that can occur due to factors such as solar exposure during the day, cooling processes at night, and atmospheric conditions. Understanding the diurnal range is crucial for studying weather patterns, plant growth, and environmental conditions, as it affects biological processes and the physical environment.

The other options do not capture this specific temperature variation. The range of temperatures across different seasons pertains to seasonal changes rather than daily fluctuations. The difference between temperatures of different regions is not related to time of day but rather geographical differences. The average temperature throughout the day summarizes the day's temperature rather than addressing the extremes between day and night. Thus, the correct answer accurately defines the concept of diurnal range.