This is related to latitude. The range of 20-30 degrees north latitude is the range of subtropical high, where the air sinks and it is difficult to form precipitation. But the temperature here is very high and the evaporation is very large, so their climate type basically belongs to tropical desert climate.
Typhoons can only be formed in tropical waters with high temperature and rich water vapor, and they are also closely related to the movement of the atmosphere. Although the temperature here is high, the air sinks mainly and there is not enough water vapor, so it is impossible to form a typhoon.