Final answer:
The highest maximum temperatures in interior deserts during July are due to increased insolation, cloudless skies, and low evaporation rates, which all contribute to extreme heat in these arid regions.
Step-by-step explanation:
The highest maximum temperatures recorded on Earth, particularly in interior deserts during July, can be attributed to a combination of factors: a) insolation is greater than at other latitudes, b) there are typically cloudless skies, and c) very little evaporation occurs to supply moisture to the atmosphere. All of these conditions are mutually reinforcing and contribute to the extreme heat observed in these regions.
High insolation in desert regions during summer is a result of the Sun being high in the sky, which means that sunlight arrives at a steep angle and heats the land much more efficiently. The lack of clouds allows for unimpeded solar radiation to reach the ground. Additionally, with low humidity and scant water sources, there is minimal evaporation to reduce temperature extremes. This scarcity of atmospheric moisture also means there is less water vapor to trap heat during the night, causing drastic temperature drops after sunset.
In humid climates, such as in Florida, evaporation of water uses up heat from the sun and the environment which helps to limit high temperatures. In contrast, arid desert regions lack the moisture necessary for this process, allowing temperatures to soar far higher than in more humid climates.