Hint: A drought is mainly caused by drier conditions as compared to normal conditions that eventually lead to water supply problems. A drought can be made worse by really hot temperatures which cause the moisture to evaporate from the soil. If a region is hot and dry, it doesn't always mean that it is going through a drought.
Complete answer: 1) Drought is caused by land and water temperatures. As the overall temperature is increased more water evaporates and severe weather conditions also increase. Landscapes and crops need more water for their survival and thus the overall demand for water increases. 2) Drought is also caused by air circulation and weather patterns. The water we have today is all the water we ever had and this water is stored in the air or on the land. Water is moved by the weather patterns in the air around. This is changing constantly. 3) Soil moisture levels also lead to drought. There is less evaporation of water for the creation of clouds when the soil moisture is depleted. Water is needed more when the surface temperature rises and less is available that contributes to a more severe drought. 4) Drought can also be caused by the demand and supply of water issues. The demand for water by people can offset or worsen the situation depending on how the region reacts especially when the weather conditions, temperatures, or air patterns push a region toward a drought. Excessive irrigation is excellent for people contributing to drought.
Note: An event of prolonged shortages in the water supply, whether atmospheric, surface water, or groundwater is called a drought. It can last for months or years or can be declared after as few as 15 days.