Hawaii Volcanoes National Park officials on Wednesday closed the park because of sulfur dioxide levels in the summit area.
Winds shifting to an east-southeasterly direction prompted the closure.
The park's closing included Kilauea Military Camp and Volcano House Hotel.
"Our primary concern is for the health and safety of visitors and employees," said Joe Molhoek of Hawaii Volcanoes National Park.
Civil Defense officials placed the Volcano Golf and Country Club Estates areas under a warning because of potential health hazards. They suggested people avoid the outdoors.
Officials also said residents in Volcano Village, Mauna Loa Estates, Ohia Estates, Royal Hawaiian Estates and Hawaiian Orchid Island Estates should keep on alert, especially those who have respiratory problems.