Outdoor air coolers work best in dry climates where the humidity is low. In areas with high humidity, the cooling effect may not be as effective, and the increased humidity may actually make the air feel more uncomfortable. Additionally, outdoor air coolers require regular maintenance, such as changing the water and cleaning the pads, to ensure that they function properly and provide clean air. This process can help reduce the temperature and increase the humidity, which can make the air feel more comfortable and refreshing.