Hawaii air quality today

Hawaii is the state whose main air pollutant comes out of the ground. Kilauea releases sulfur dioxide continuously, and USGS has reported emissions on the order of 1,000 to 5,000 tonnes a day even while the summit eruption is paused between episodes. Output rises further during the short, intense lava fountaining episodes the volcano has been running in sequence. Sulfur dioxide converts in the atmosphere to fine sulfate droplets, and the haze that results has its own local name, vog.

Where it goes is decided by the wind. Northeasterly trade winds, which blow most days in summer, push the plume southwest across Hawaii Island and stack it against the leeward Kona coast, where daytime heating over Mauna Loa and Mauna Kea pulls it back into an eddy offshore instead of flushing it out. When the trades break down and the flow turns southerly — Kona winds — the plume travels up the island chain instead, and Maui and Oahu take a share. Islands a long way from the vent can get their worst air from it.

On the state side, the Hawaii Department of Health’s Clean Air Branch operates the monitors, including the sulfur dioxide sites on Hawaii Island nearest the vent, publishes their ambient readings, and issues public advisories when Kilauea is active. We have not written a page for Honolulu, Hilo or Kailua-Kona, so the table above is the whole of what this site knows about Hawaii.