Kilauea went to watch level as lava spilled over before its 55th fountaining episode

The U.S. Geological Survey has raised its alert level for Kilauea after lava began spilling over one of the volcano’s vents, a precursory sign that the Hawaiian volcano is approaching its 55th fountaining episode since its current eruption began in late 2024. The Hawaiian Volcano Observatory moved Kilauea’s alert status from ADVISORY to WATCH and its aviation color code from YELLOW to ORANGE, a shift that signals eruptive activity is imminent even though the dramatic lava fountains themselves had not yet started as of the notice. The change keeps Hawaii Volcanoes National Park and nearby communities on alert for volcanic gas and ash fallout even before the main event begins.

What triggered the shift from advisory to watch

According to the notice issued by the Hawaiian Volcano Observatory, precursory low-level eruptive activity began around 12:45 p.m. Hawaii time on September 7, with a sluggish overflow of lava from the north vent inside Halemaʻumaʻu crater. That kind of overflow typically precedes a full fountaining episode by hours to days, giving scientists a window to raise public alerts before the more intense phase arrives. The observatory initially forecast the fountaining episode to begin sometime between September 7 and September 10.

All of the activity remains confined to Halemaʻumaʻu crater within Hawaii Volcanoes National Park, an area that has been closed to the public since 2007 because of ongoing hazards from crater-wall instability, ground cracking, and rockfalls. That closure means the eruption itself poses little direct danger to visitors or residents, but the gas and ash it produces can travel well beyond the park boundary, a point the observatory’s official notice underscored in its hazard guidance.

The volcano’s 55th episode in an eruption that began in 2024

Kilauea’s current eruptive sequence has been ongoing since December 2024, and each fountaining episode has followed a broadly similar pattern of building pressure, a burst of lava fountains, and then a pause before the cycle repeats. Most episodes since the eruption began have lasted a day or less, which has allowed both scientists and Hawaii residents to become familiar with the rhythm even as the exact timing of each new episode remains difficult to predict precisely.

The precursory overflow pattern observed ahead of episode 55 continued for several days beyond the initial forecast window, with dozens of individual overflow events recorded at the north vent as monitoring continued. That kind of extended runway before an episode actually begins is not unusual for Kilauea’s recent activity, but it does mean the watch-level alert can remain in place for longer than the observatory’s original estimate suggested. Scientists have described the irregular pace of summit inflation between overflows as one of the harder variables to pin down, since the timing of the eventual fountaining episode depends on how quickly pressure rebuilds beneath the crater floor rather than on a fixed schedule.

The hazards a fountaining episode brings for the surrounding area

Lava fountaining at Kilauea produces several distinct hazards beyond the flows themselves. Volcanic gas, primarily sulfur dioxide, reacts in the atmosphere to create vog, or volcanic air pollution, which can drift downwind and cause respiratory and eye irritation for people well outside the immediate eruption zone. Tephra, the glassy volcanic fragments produced by fountaining, falls heaviest within about three miles of the vents, though lighter particles and strands of volcanic glass known as Pele’s hair can be carried much farther by the wind.

The observatory’s notice specifically flagged that light winds from the south had the potential to carry volcanic fumes, and possibly tephra once fountaining begins, northward past the rim of Kaluapele, Kilauea’s summit caldera. Residents and visitors in the path of that drift are advised to minimize exposure to airborne ash and glass particles, which can irritate skin, eyes, and airways even in relatively small concentrations. Scientists have also asked residents who notice tephra fall in their area to report it through a dedicated online form, a crowdsourced approach that helps the observatory map how far the lightest volcanic particles travel beyond the immediate hazard zone.

How officials and residents are tracking the eruption’s progress

The Hawaiian Volcano Observatory has continued issuing updated notices as the precursory activity evolved, adjusting its forecast window for when full fountaining would begin as new data on summit inflation and vent behavior came in. That ongoing series of notices, along with the observatory’s regularly updated Kilauea status page, has become the primary way both scientists and the public track the volcano’s day-to-day behavior during this drawn-out lead-up to episode 55.

Live webcam feeds covering the summit crater give both scientists and the public a way to watch for the moment fountaining actually begins, since the observatory has said it will issue a new notice as soon as episode 55 is confirmed underway. Until then, the elevated watch-level alert and orange aviation code remain the clearest public signal that Kilauea’s next eruptive episode, whenever it arrives, is close.

This article was created with the assistance of AI and reviewed by an editor.

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