Kīlauea remains at Volcano Alert Level WATCH and Aviation Color Code ORANGE, according to the Hawaiian Volcano Observatory daily update issued Monday, Sept. 14, at 9:37 a.m. HST. The lava fountaining episode forecast for last week still had not started. HVO said the current precursory period, at 6.8 days, is the longest since high fountains began after episode 4, and it now says there is "no way to forecast when or if episode 55 fountains will start."

That is a shift from a dated forecast window to an open-ended wait. The observatory's volcanic activity notice on Sept. 7 forecast fountaining between Sept. 7 and 10, and a later message moved the window to Sept. 10 and 11. Both passed. Slow summit inflation stalled on the night of Sept. 13, and eruptive activity slowed significantly after 6 a.m. HST on Sept. 14.

The hazard picture has not changed. HVO says the episodic eruption is occurring within a closed area of Hawaiʻi Volcanoes National Park. What has changed is predictability, which matters for residents downwind and visitors planning trips.

Spatter Cone Replaces the Lava Overflows

Between Sept. 7 and 12, the north vent in Halemaʻumaʻu produced 104 precursory overflows. They lasted from a few minutes to about two hours, separated by pauses of about 15 minutes to eight hours. On Sept. 11 and 12, dome fountains feeding the overflows grew from 15 to 30 feet (5 to 10 meters) to 35 to 50 feet (10 to 15 meters) tall. One of the main flows reached about half a mile (1 kilometer) southwest of the vent.

On Sept. 13, the style changed. Spatter bursts began building a small cone on the north vent rim around midday, and by evening observatory messages described nearly continuous bursts, with larger ones reaching 35 to 70 feet (10 to 20 meters). HVO called this Strombolian activity, with large individual bursts one after another like fireworks, rather than the continuous lava of a Hawaiian-style fountain.

HVO explained that the eruption cooled lava in the upper conduit, making it more viscous. Gas then gathered into larger bubbles that drove bigger bursts. The observatory said this dense, degassed magma likely must be pushed out of the vent or recycled into the magma chamber below before fountaining can start.

A Tiltmeter Signal That No Longer Sets the Clock

HVO tracks summit ground tilt on the Uēkahuna tiltmeter, known as UWD. Episode 54 on Aug. 25 removed 12.7 microradians of tilt. Since then, the summit has regained more than two microradians beyond that amount, a sign HVO has cited as favorable for another episode.

This time, the extra inflation has not been enough. HVO said reinflation has been very unsteady since episode 54. Tilt peaked on Sept. 7, dipped by about one microradian as the precursory flows began and showed little net change until slow inflation resumed around 9 p.m. HST on Sept. 10. That inflation stalled again on the night of Sept. 13.

Nature World News previously reported on the alert increase and the variable gap between precursors and fountains. The new development is that this precursory phase has now outlasted the previous longest one, 6.2 days before episode 44. The observatory also notes that several summit monitoring stations remain offline after earlier power and storm outages.

Hazards Downwind of Halemaʻumaʻu

Between episodes, sulfur dioxide output from the summit typically ranges from 1,000 to 5,000 tonnes per day, forming vog downwind. On Sept. 14, light trade winds of less than about 10 mph pushed the plume southwest. HVO's models indicated that gas, fine ash and Pele's hair would travel south of Kaluapele, the summit caldera, if fountaining began that day.

That direction matters for the Kaʻū district, where HVO received a report of trace Pele's hair during episode 54. That episode sent fountains about 500 feet (150 meters) high and a plume to roughly 17,000 feet above sea level. Vog and sulfur dioxide may cause respiratory problems, and people with asthma or other breathing conditions should take particular care. The International Volcanic Health Hazard Network offers exposure guidance.

The caldera rim around Halemaʻumaʻu has been closed to the public since late 2007 because of crater wall instability, ground cracking and rockfalls. A felt magnitude 3.9 earthquake near Pāhala on the morning of Sept. 13 was not related to the eruption, HVO said.

Planning Around an Open-Ended Wait

Kīlauea has erupted episodically from Halemaʻumaʻu since Dec. 23, 2024, with most fountaining episodes lasting less than a day. Residents and visitors can follow HVO daily updates, the eruption timeline and USGS summit livestreams. Anyone planning a trip should check Hawaiʻi Volcanoes National Park for closures before driving. People downwind should minimize exposure to tephra, which can irritate skin, eyes and lungs, and those who use respiratory medication should keep it close. Instructions from the Hawaiʻi County Civil Defense Agency take priority.

The ORANGE aviation code is directed at pilots, so airline passengers should simply watch for carrier advisories.

HVO has said it will issue a new notice when fountaining begins and will continue daily updates. Magma remains shallow in all of the vents, and HVO says conditions remain favorable for episode 55, but its timing is genuinely uncertain.

Timeline of Key Developments

Sept. 14, 2026, 9:37 a.m. HST: HVO reports stalled inflation and slowed activity and says the start of episode 55 cannot be forecast.

Sept. 13, 2026, evening: Nearly continuous spatter bursts from the north vent reach 35 to 70 feet.

Sept. 13, 2026, 8:00 a.m. HST: A felt magnitude 3.9 earthquake near Pāhala is judged unrelated to the eruption.

Sept. 12, 2026: The last precursory overflow brings the total since Sept. 7 to 104.

Sept. 11, 2026, 7:42 a.m. HST: HVO says episode 55 could start that day if inflation remains consistent.

Sept. 10, 2026: HVO moves the flooding forecast to Sept. 10 and 11.

Sept. 7, 2026, 1:00 p.m. HST: HVO raises the alert to WATCH and ORANGE after precursory overflows begin, forecasting fountains for Sept. 7 to 10.

What Readers Want to Know

Is Kīlauea erupting right now? Low-level precursory activity continues at the summit, but a lava fountaining episode 55 had not begun as of HVO's Sept. 14 update.

What is the current alert level? Volcano Alert Level WATCH and Aviation Color Code ORANGE, as of 9:37 a.m. HST on Sept. 14.

Why can't HVO forecast the next episode? Inflation stalled, and dense, degassed magma in the vent likely needs to clear before fountaining can start.

Which areas could see vog or Pele's hair? With the light trade winds reported on Sept. 14, areas south and southwest of the summit, including parts of Kaʻū.

Is the eruption threatening homes? HVO says the eruption is occurring within a closed area of Hawaiʻi Volcanoes National Park, with lava confined to the summit area.