Water samples indicate that the lake has a pH of 4.2 (moderately acidic, in the range of many fruit juices) and high concentrations of dissolved sulfur and magnesium. The depth of the lake is approximately 35 meters (115 feet) and growing. It is approximately 107 meters (~351 feet) wide by 211 meters (~692 feet) long. The water has a temperature of about 70 degrees Celsius (158 degrees Fahrenheit). The water in Halema‘uma‘u is not visible from publicly accessible areas of Hawai‘i Volcanoes National Park, but HVO now has webcams that provide a direct view of the pond.