Six new vents opened on and near the northwest wall of Kilauea's Halemaumau crater between the night of Sept. 14 and the evening of Sept. 16, shifting the volcano's summit eruption away from the fountaining pattern it has followed for most of the past 20 months. The sixth vent appeared on the crater floor just north of vent 5 and was visible shortly before 6 p.m. HST on Sept. 16, the USGS Hawaiian Volcano Observatory (HVO) said, adding that a small drop in summit tilt that began around 5 p.m. HST may be connected.

By early Sept. 17, the new openings had quieted. In a message posted at 1:12 a.m. HST, HVO said summit tremor and tilt began decreasing around 5 p.m. HST on Sept. 16, the new vents stagnated at about 8:30 p.m. HST, and the established north, south and west vents glowed strongly with flames through the night. HVO reported no unusual activity or earthquakes elsewhere on the volcano.

The first new vent opened at 8:36 p.m. HST on Sept. 14 at the base of the crater's northwest wall and began feeding a lava flow around 9 p.m. HST. None of the new vents produced high fountains, and all activity has remained inside a closed area of Hawaii Volcanoes National Park. Kilauea's Volcano Alert Level remains WATCH, and its Aviation Color Code remains ORANGE.

The change matters because HVO has built its forecasts on a reliable cycle in which the summit swells and then deflates during each fountaining episode. That cycle now looks less predictable. "The summit region continues to be highly pressurized, but it is not possible to forecast what might happen next," HVO wrote on Sept. 16 in its morning daily update.

Pressure Builds While the Main Vents Hold Back

Nature World News previously reported that HVO raised Kilauea to WATCH as lava overflowed the north vent, after precursory overflows began around 12:45 p.m. HST on Sept. 7. HVO's first forecast window for episode 55 fountaining, Sept. 7 to 10, passed without high fountains. Instead, the north vent produced 104 precursory overflows between Sept. 7 and 12, followed by spatter bursts that built a small cone measured at 36 to 39 feet (11 to 12 meters) tall on the afternoon of Sept. 14.

As of Sept. 16, precursory activity had lasted about nine days, the longest such stretch since high fountains began after episode 4 in January 2025. The next longest was 6.2 days before episode 44. The Uekahuna (UWD) tiltmeter had recorded 15.7 microradians of inflation since episode 54, well above the 12.7 microradians lost during that episode, but inflation had been essentially stalled since the new vents opened.

HVO's status report on the new vents, issued the afternoon of Sept. 15, said the pressurization may reflect the growing height of the north, south and west vent complex, which has risen about 500 feet (150 meters) since the eruption began on Dec. 23, 2024. The new vents sit about 150 feet (45 meters) below the level of the north vent and opened without significant seismicity, in the area of a brief swarm of shallow earthquakes on the night of Sept. 13.

Seismic signals also picked up. Tremor at the summit nearly doubled in the 24 hours before the Sept. 16 morning update, though HVO said the increase could not be tied directly to any surface change. Twelve earthquakes were recorded beneath the summit in that period. Nearly 100 have been located since Sept. 7, most smaller than magnitude 2, with the largest a magnitude 2.6 on Sept. 11. A felt magnitude 3.9 earthquake near Pahala on the morning of Sept. 13 was not related to the eruption, HVO said.

Six Vents, Six Different Behaviors

The vents have behaved differently. Vent 2 opened about 100 feet up the crater wall at 8:46 p.m. HST on Sept. 14, produced tiny flows that quickly stagnated, then reactivated at 12:30 a.m. HST on Sept. 16 with a small dome fountain feeding a lava fall onto the crater floor. Vent 3, about 200 feet higher on the tephra-covered slope, fed a flow that reached the crater floor before stagnating. Vent 4 opened at 8:52 a.m. HST on Sept. 15 and fed the largest flow that day.

Vent 5 opened at 8:58 p.m. HST on Sept. 15 and produced no lava flow, but its bursts of flame and spatter, which lasted until about 4 a.m. HST, excavated a small crater in the hillside. The original north vent kept producing intermittent spatter, and the south and west vents continued to glow with occasional bursts.

HVO's status report laid out four possible outcomes, drawing on the 1983 Puu Oo and 1969 Mauna Ulu eruptions, both of which continued after fountaining episodes ended as nearby fissures erupted more continuous flows. Lava could erupt continuously within Halemaumau. Fountaining could resume from an existing vent at any time. Magma could open more new vents in the summit area. Or magma could intrude into the upper Southwest or East Rift Zone, which HVO said would be signaled by earthquakes migrating away from the summit along with summit deflation. In its Sept. 16 update, HVO said the two most likely possibilities were continuous eruption from the new vents, or the new vents shutting down and all activity returning to the established vents.

For context, episode 54 on Aug. 25 lasted about nine hours and sent fountains about 500 feet (150 meters) high. Most tephra fell inside the closed park area, though HVO received a report of trace Pele's hair in the Kau district.

Downwind Communities and Park Visitors Face the Main Exposure

The eruption poses no direct lava threat to homes, but airborne hazards reach farther. Between episodes, the summit typically releases 1,000 to 5,000 tonnes of sulfur dioxide per day, which reacts in the atmosphere to form vog. Trade winds of 10 miles per hour (16 kilometers per hour) or more were pushing the gas plume southwest of the caldera on Sept. 16, and HVO's models showed that gas, fine ash and Pele's hair would move south of the caldera if fountaining began that day.

People with asthma or heart and lung conditions, young children, and older adults in downwind areas face the greatest risk from vog. Households that rely on rainwater catchment should also pay attention, since tephra and Pele's hair can settle on roofs and in tanks during fountaining. HVO says tephra can irritate the skin, eyes, and airways. Near the caldera, crater walls and tephra-covered slopes are prone to cracking and small landslides, which is why the rim around Halemaumau has been closed to the public for years.

Checking Livestreams and Official Updates Before Heading Out

For people hoping to see the eruption, HVO's three summit livestream cameras and webcams are the safest way to watch, and HVO recentered its V2 camera on the new vents on Sept. 15. Visitors should check the Hawaii Volcanoes National Park website for open areas and stay out of closed zones. Downwind residents can track conditions on the vog information dashboard linked by HVO and should follow Hawaii County Civil Defense guidance.

Canceling a trip to the island is not warranted based on current information. Hawaii County Civil Defense and the national park, not social media, make access and safety decisions.

HVO publishes a daily update each morning and posts significant changes as observatory messages between updates, and a Volcano Activity Notice will follow any major change. The key unknowns are whether the new vents resume, shut down for good, or give way to high fountains. HVO also noted that several summit monitoring stations remain offline after earlier power and storm outages. Nature World News will update this story as HVO reports new activity.

Developing Story Timeline

Sept. 17, 2026, 1:12 a.m. HST: HVO reports that summit tremor and tilt began decreasing around 5 p.m. HST on Sept. 16 and that the new vents stagnated at about 8:30 p.m. HST.

Sept. 16, 2026, about 6 p.m. HST: Vent 6 is visible on the Halemaumau crater floor, according to HVO's 8:09 p.m. HST message.

Sept. 16, 2026, 10:16 a.m. HST: HVO's daily update reports tremor nearly doubled and inflation stalled. The alert level stays at WATCH and ORANGE.

Sept. 15, 2026: Vent 4 opens at 8:52 a.m. HST; HVO issues a status report outlining four possible outcomes that afternoon, and vent 5 opens at 8:58 p.m. HST.

Sept. 14, 2026, 8:36 p.m. HST: Vent 1 opens at the base of the northwest wall, followed by vent 2 at 8:46 p.m. HST.

Sept. 7, 2026, about 12:45 p.m. HST: Precursory overflows begin from the north vent, and HVO raises Kilauea to WATCH and ORANGE.

The bottom line: Kilauea's summit is pressurized beyond the level that usually triggers fountaining, yet the eruption vented through a cluster of new openings instead, and those openings had stalled by the night of Sept. 16. HVO says it cannot forecast what happens next. Downwind residents with breathing conditions should watch air quality, visitors should rely on the livestreams, and everyone should follow HVO and Hawaii County Civil Defense for the next change.

What Readers Want to Know

What changed at Kilauea this week? Six new vents opened on and near Halemaumau's northwest wall between the night of Sept. 14 and the evening of Sept. 16, north of the established vent complex. Several fed small lava flows on the crater floor, and HVO said the new vents stagnated around 8:30 p.m. HST on Sept. 16.

Has episode 55 fountaining started? No. As of HVO's latest messages, high fountaining had not begun, and HVO said it cannot forecast whether or when it will.

What is the current alert level? Volcano Alert Level WATCH and Aviation Color Code ORANGE, unchanged since Sept. 7.

Are homes at risk from lava? HVO reports all activity is confined to Halemaumau crater inside a closed area of Hawaii Volcanoes National Park, with no unusual activity in the rift zones.

Who should take precautions? Downwind residents with asthma or heart and lung conditions, young children, older adults, and households with rainwater catchment systems, because of volcanic gas, vog, and possible tephra fall.

Where can I watch the eruption safely? HVO's summit livestreams and webcams show the vents. Visitors should check the national park website for open areas.

When is the next update? HVO issues a daily update each morning HST and posts observatory messages when significant changes occur.