Lava fountains over 150 m (500 feet) in new eruption at Kilauea, Hawaii
A new eruptive episode started at Kīlauea’s Halemaʻumaʻu crater at 13:11 UTC (03:11 HST) on September 19, 2025, producing lava fountains over 150 m (500 feet) and a volcanic plume up to 3 000 m (10 000 feet) high. The eruption remains confined to the summit caldera within Hawaiʻi Volcanoes National Park.
Kilauea volcano eruption on September 19, 2025. Credit: USGS/HVO
Episode 33 of the ongoing summit eruption was preceded by spattering and lava overflows between September 16 and 18, along with dome fountains 3–6 m (10–20 feet) high and episodic gas bursts producing spatter up to 10 m (30 feet).
According to HVO, continuous low fountains began at 02:44 HST on September 19, intensifying until 03:11 HST when seismic tremor and tilt data confirmed the start of the new episode.
By 03:30 HST, fountains from the north vent continued to reach heights around 150 m (500 feet) and fed multiple lava streams onto the crater floor. Tiltmeters showed a switch from inflation to sharp deflation, marking withdrawal of magma from storage as eruption intensity increased.
The eruption plume is currently 3 000 m (10 000 feet) above sea level, with past episodes having produced plumes up to 6 000 m (20 000 feet). Winds are carrying emissions southwest across the Kaʻū desert inside Hawaiʻi Volcanoes National Park. Airports at Hilo (ITO) and Kona (KOA) remain unaffected.
Hazards include high levels of volcanic gases, primarily sulfur dioxide (SO2), which reacts in the atmosphere to form vog (volcanic smog) that can spread far downwind. During eruptive episodes, SO2 emission rates can rise sharply.
While typical values at Kīlauea’s summit are often below 14 000 tonnes per day, episodic surges have been reported at much higher levels.
Fallout of Pele’s hair, strands of volcanic glass, has been observed in previous episodes up to 15 km (10 miles) from the vent. These can cause skin and eye irritation and should be avoided. Other volcanic fragments such as pumice, scoria, and ash generally fall within 1–3 km (1–2 miles) of the crater.
Local hazards remain around Halemaʻumaʻu from unstable crater walls, ground cracking, and rockfalls, which can be triggered by earthquakes in the summit area.
Lava flows remain confined to Halemaʻumaʻu crater and the southwest side of Kaluapele, consistent with other episodes in this eruption sequence.
Since December 23, 2024, the summit eruption has consisted of episodic lava-fountaining events, typically lasting less than a day and separated by pauses of several days. No changes have been detected in the East Rift Zone or the Southwest Rift Zone during the current activity.
Kīlauea’s Volcano Alert Level remains at WATCH, and the Aviation Color Code is Orange.
References:
1 Volcano Observatory Notice for Aviation (VONA): Kīlauea (VNUM #332010) – USGS/HVO – September 19, 2025.
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