Final answer:
Over a barren area on a hot day, the air would be warm and dry due to high temperatures, high evaporation rates, and low annual precipitation typical of desert-like environments.
Step-by-step explanation:
On a hot day over a barren area, you would expect the air to be warm and dry. Barren areas like deserts have high temperatures during the day because of the absence of vegetation and moist soils that could contribute to evaporative cooling. The evaporation rate from the skin's surface is higher in humid conditions, but since barren areas are typically associated with low humidity, this is not the case here. Instead, these areas have low annual precipitation and high evaporation, leading to dry air conditions. For example, subtropical deserts can experience temperatures above 60°C (140°F) during the day and close to 0°C (32°F) at night, largely due to the lack of water vapor in the air which would otherwise trap heat.