Palau has a tropical climate with annual rainfall of about 150 inches. The climate tends to be drier during El Nino years. Rain falls throughout the year, though January through March are usually the driest months. Palau is outside the normal typhoon track, but from June to November a tropical storm can settle over the country and dump heavy amounts of rain for several days. The temperature averages range from a high of 87 degrees to a low of 77 degrees year round. Humidity is high, ranging from 86% to 91%, and non-air conditioned environments can get moldy. Air quality is excellent and free of pollutants.