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USGS Volcano Notice - DOI-USGS-HVO-2025-10-17T05:15:25+00:00

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HVO/USGS Volcanic Activity Notice

Volcano: Kilauea (VNUM #332010)

Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Issued: Friday, October 17, 2025, 8:35 PM HST
Source: Hawaiian Volcano Observatory
Notice Number: 2025/H450
Location: N 19 deg 25 min W 155 deg 17 min
Elevation: 4091 ft (1247 m)
Area: Hawaii

Volcanic Activity Summary:

During the lapse in appropriations, the USGS Hawaiian Volcano Observatory (HVO) continues to maintain monitoring networks and issue updates and notifications of volcanic activity via the Hazard Notification Service. Volcano monitoring data will continue to be available on the HVO website. Static website content will not be updated until further notice and information may become outdated over time. For more information on the shutdown, please visit the Department of the Interior website at www.doi.gov.

Episode 35 of the ongoing Halemaʻumaʻu eruption began at approximately 8:05 p.m. HST on October 17, 2025. Sustained lava fountains approximately 500 feet (150 meters) in height are currently erupting from the north vent. Fountain heights are increasing rapidly and angled to the northeast.

Past episodes have produced incandescent lava fountains over 1000 feet (300 meters) high that produce eruptive plumes up to 20,000 feet (6000 meters) above ground level.  According to the National Weather Service, overnight winds are blowing from the north, which suggests that volcanic gas emissions and volcanic material may be distributed south of Kilauea summit. 

  • All eruptive activity is confined to Halemaʻumaʻu crater within Hawaiʻi Volcanoes National Park; commercial airports in Hawaii County (KOA and ITO) will not be affected by this activity.
  • Three Kīlauea summit livestream videos that show eruptive lava fountains are available here: V1cam, V2cam, V3cam
  • KPcam and MKcam provide views of the plume height for aviation purposes

Episode 35 was preceded by a series of lava overflow-drainback events at the south vent beginning on October 16 at 7:35 a.m. and continous lava overflows from the north vent beginning tonight at 7:28 p.m with 20-30 feet (10-15 meters) high fountains. The volume and vigor of sustained fountains and flows from the north vent increased significantly just after 8:00 p.m.

Seismic tremor increased significantly, and summit tilt switched from inflation to deflation at about the same time that sustained fountaining began. Inflationary tilt reached approximately 24 microradians since the end of the last episode.

Most episodes of Halemaʻumaʻu lava fountaining since December 23, 2024, have continued for around a day or less and have been separated by pauses in eruptive activity lasting generally at least several days. 

No changes have been detected in the East Rift Zone or Southwest Rift Zone. 

Kīlauea Volcano Alert Level/Aviation Color Code remain at WATCH/ORANGE. All current and recent activity is within Hawaiʻi Volcanoes National Park.

Recent Observations:
[Volcanic cloud height] Plume in past episodes has reached up to 20,000 feet (6000 meters) above ground level, driven by incandescent lava fountains over 1000 feet (300 meters) high
[Other volcanic cloud information] Most volcanic ash and pumice (tephra) will fall within about 1 mile (1-2 km) of the eruptive vents. Lower concentrations of finer volcanic particles, such as ash and Pele's Hair, can be transported greater distances downwind of the vent (20 miles or 30 km). Sulfur dioxide emission rate is typically 50,000 tonnes/day during eruptive episode.
[Ballistics] N/A
[Lava flow/dome] N/A
[Lava flow] Confined to Halemaʻumaʻu (within summit caldera).

Hazard Analysis:
[Ashfall] Small volcanic particles may impact downwind areas.
[Lava flow/dome] N/A
[Pyroclastic flow] N/A
[Mud flow] N/A
[Volcanic gas] Typically 50,000 tonnes/day during sustained lava fountaining episode.
[Lava flow] Confined to Halemaʻumaʻu (within summit caldera).

Remarks:

Hazard Analysis: 

This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park. High levels of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are one hazard of concern, as this hazard can have far-reaching effects downwind. As SO2 is continuously released from the summit during an eruption, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) downwind of Kīlauea. SO2 and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/

Another hazard closer to the vent is fallout of Pele's hair and other volcanic fragments from lava fountains. Pele's hair is strands of volcanic glass often produced by lava fountaining activity and can be carried well over 10 miles (15 kilometers) from the vent. Other hot glassy volcanic fragments including Peleʻs hair, volcanic ash, pumice, scoria, and reticulite can fall on the ground within 1-2 miles (1-3 kilometers) of the eruptive vent(s) with the highest concentrations downwind of the vent(s). Pumice and other volcanic fragments have fallen on Highway 11 west of Hawaiʻi Volcanoes National Park depending on wind and eruption conditions.  Strong winds may waft light particles, including Pele's hair, to greater distances downwind. Once they are on the ground, Pele's hair can sometimes cluster and tangle together, giving it the appearance of a tumbleweed. The extent of Pele's hair deposition is dependent on lava fountaining activity and current wind conditions. Residents and visitors should minimize exposure to Pele's hair and other glassy volcanic fragments, which can cause skin and eye irritation. More information about how Pele's hair, its hazards, and what to do is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards. A recently updated Frequently Asked Questions document that includes information about potential health effects of Pele's hair is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf

Hawaiian lava flows generally advance slowly downslope, and during this eruption flows have been confined to Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera. 

Other significant hazards also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. This underscores the extremely hazardous nature of Kīlauea's caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since late 2007.



Contacts:

askHVO@usgs.gov



Next Notice:

HVO continues to closely monitor Kīlauea and will issue a VAN/VONA at the start of the next eruptive episode. If possible, HVO will also issue a Status Report beforehand at the onset of low-level precursory activity. Regularly scheduled daily updates for Kīlauea are posted on the HVO website at https://www.usgs.gov/volcanoes/kilauea/volcano-updates  

More Information:



Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Summary of volcanic hazards from eruptions: https://www.usgs.gov/observatories/hvo/hazards
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hvo
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes