Humidity is higher in the southeastern U.S. due to the influence of the Gulf of Mexico.

The southeastern United States experiences higher humidity levels compared to the southwestern U.S. largely because of the influence of the Gulf of Mexico. The Gulf provides a constant source of warm, moist air that flows into the region, especially during the warmer months. As this moisture-laden air moves inland, it raises humidity levels, particularly in states like Florida, Louisiana, and Alabama. In contrast, the southwestern U.S., such as Arizona and New Mexico, is typically drier because of its distance from moisture-rich bodies of water and the arid desert landscape that dominates the region.