USGS Volcano Notice - DOI-USGS-HVO-2026-08-26T17:33:36+00:00

Overview:

The summit eruption of Kīlauea in Halemaʻumaʻu is paused following 9 hours of continuous lava fountaining during episode 54 on August 25, 2026. Summit inflation resumed after the episode ended, but mild deflation began at 2:00 a.m. HST this morning. Glow has been visible in the north and west vents. These observations indicate that another lava fountaining episode is likely in the coming weeks, but more inflationary tilt data are needed to determine the precise forecast.

A detailed account of lava fountaining episode 54 is posted below.

No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.

NOTE: Significant changes in activity between Daily Updates are posted here: https://www.usgs.gov/observatories/hvo/observatory-messages

Summit Observations:

Glow and occasional flames were visible overnight from both the north and west vents in Halema’uma’u. Around 2:00 a.m. HST, the north vent dimmed slightly, while glow at the west vent became weaker and more sporadic. The south vent remained dark overnight, and it appears to be partially filled in by north vent spatter erupted yesterday. Lava flows along the north and south sides of Halemaʻumaʻu crater continued to advance after episode 54 ended. However, they slowed greatly in the early morning and by dawn only a few points of incandescence were still visible in webcam views. A small, slump-driven flow was active on the south side of the west vent from around 2:30 a.m. HST until dawn. Slow movements from cooling lava flows and gravity-induced slumps on the vents may continue over the coming days and nights. 

Low-frequency seismic bursts began with the cessation of episode 54 and they continue this morning, which is typical during the early stages of pauses between eruptive episodes. Three shallow earthquakes have been recorded beneath the summit region over the past 24 hours. 

Summit inflation resumed immediately upon the cessation of lava fountaining, and the Uēkahuna (UWD) tiltmeter recorded a peak of 1.4 microradians of inflation prior to the onset of mild deflation around 2:00 a.m. HST. As of this morning, UWD has recovered a total of 0.9 microradians of inflationary tilt since the end of the episode. Deflationary tilt measured on UWD totaled 12.7 microradians during episode 54.

During inter-episode pauses, the sulfur dioxide (SO₂) emission rate from the summit typically varies between 1,000 and 5,000 tonnes per day. Strong trade winds are pushing the degassing plume to the southwest over the Kaʻū Desert this morning.

Rift Zone Observations:

Rates of seismicity and ground deformation remain low in the East Rift Zone and Southwest Rift Zone. SO₂ emissions from the East Rift Zone remain below the detection limit.

Analysis:

The abrupt switch from summit deflation to inflation at the end of episode 54 and continued glow from the eruptive vents indicate that another lava fountaining episode is likely in the coming weeks. However, the onset of a deflationary step around 2:00 a.m. HST this morning indicates that unpredictable, stepwise inflation will likely continue during this repose period, as it has since episode 51. More inflationary tilt data are needed to model the precise forecast window.

Kīlauea has been erupting episodically since December 23, 2024, from two vents (north and south) in Halema‘uma‘u. Lava fountaining episodes, which generally last for less than 12 hours, are separated by pauses of two or more weeks.

HVO continues to closely monitor Kīlauea and is in contact with Hawai‘i Volcanoes National Park and the Hawai‘i County Civil Defense Agency about eruptive hazards.

Please see the Hawaiʻi Volcanoes National Park website for visitor information: https://www.nps.gov/havo/index.htm

Summary of episode 54:

A detailed account of episode 54 is given in the HVO Status Report issued on August 25: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-08-26T05:56:38+00:00

• Episode 54 of the ongoing Halemaʻumaʻu eruption began around 10:30 a.m. HST and ended at 7:33 p.m. HST on August 25, 2026, after 9 hours of continuous lava fountaining. 
• The maximum lava fountain height from the north vent was approximately 500 feet (150 meters) above ground level, reached between 12:15 p.m. and 1:00 p.m. HST. Neither the south vent nor the new west vent (formerly the collapse pit) fountained during this episode.
• The maximum plume height was approximately 17,000 feet (5,200 meters) above sea level.
• Most tephra fall was restricted to the closed area of Hawaiʻi Volcanoes National Park, southwest of the active eruptive vents in Halemaʻumaʻu. However, HVO did also receive a report of trace Pele’s hair falling in the Ka‘ū district of the Island of Hawaiʻi.

Resources:

NOTE: HVO’s monitoring network is mostly recovered from recent power- and storm-related outages. Several summit stations will remain offline as we continue working to repair instruments and re-establish connections in our monitoring network.

The following links provide more information about the current eruption that began on December 23, 2024:

• Eruption resources, including the most recent map and a timeline of eruption episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information
• Short messages tracking the evolution of the lava fountains and eruptive activity can be found here: https://www.usgs.gov/observatories/hvo/observatory-messages
• Three Kīlauea summit livestream cameras that show eruptive lava fountains are available here: https://www.youtube.com/@usgs/streams
• Summit eruption webcams: https://www.usgs.gov/volcanoes/kilauea/summit-webcams
• Volcano Watch article on gas pistons: https://www.usgs.gov/observatories/hvo/news/volcano-watch-so-what-earth-or-least-kilauea-a-gas-piston

Hazards:

This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park.

• Volcanic Gas: high levels of volcanic gas—primarily water vapor (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂)—are continually released during an eruption. Emissions can remain locally hazardous in the areas immediately downwind of the vents, even when the vents are not actively erupting. SO₂ reacts in the atmosphere to create vog (volcanic air pollution) downwind. SO₂ and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/
• Tephra: small glassy volcanic fragments—volcanic ash, pumice, scoria, Pele’s hair and reticulite—are created by the lava fountains. A combination of fountaining dynamics and wind conditions determines where tephra fall may occur for any given eruption episode. Larger particles fall near the vents while light particles may be wafted greater distances. These particles may be remobilized during windy conditions following recent eruptive episodes. Residents and visitors should minimize exposure to these fragments, which can cause skin, eye, and respiratory irritation. More information and guidance on tephra fall hazards is available at https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/
• Lava flows: lava on the floor of Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera, remains hot and may slowly move in the days immediately following an eruptive episode.

Other significant hazards exist around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes. Close to the eruptive vents, the tephra material on the crater rim is prone to cracking, slumping, and small landslides that sometimes expose hot and molten material within. 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.