Halemaʻumaʻu eruption · episode 39 of 55
Kīlauea episode 39
Episode 39 of Kīlauea's Halemaʻumaʻu eruption began at 8:10 p.m. HST on December 23, 2025 and ended at 2:13 a.m. HST on December 24, 2025. USGS gives the duration as 6 hours. HVO's Uēkahuna tiltmeter (UWD) recorded about 26.8 microradians of deflation during the episode. HVO notes: North and south vents active.
Episode 39 at a glance
- Start (HST)
- December 23, 2025, 8:10 p.m.USGS timeline
- End (HST)
- December 24, 2025, 2:13 a.m.USGS timeline
- Duration
- 6 hoursUSGS timeline
- UWD tilt (deflation)
- about 26.8 microradiansHVO notice
- Max fountain height
- about 407 mUSGS timeline
- Lava erupted
- about 9.3 million m³USGS timeline
- Pause that followed
- 19 daysUSGS timeline
Start: the USGS timeline gives “December 23, 2025 - 8:10 p.m.”, but an HVO notice at the time said: “Activity Summary: Episode 39 fountaining began yesterday at 8:20 p.m. HST, December 23, almost 1 year to the day on the anniversary of the ongoing episodic eruption that began at 2:20 a.m. HST on December 23, 2024.”
In HVO's words
The sentences these figures come from, quoted from USGS Hawaiian Volcano Observatory notices.
“The Uēkahuna tiltmeter (UWD) recorded about 26.8 microradians of deflationary tilt during episode 39.”
HVO notices about episode 39
- Volcano Activity Notice · Dec 23, 2025, 8:27 p.m. HST
- Volcano Activity Notice · Dec 24, 2025, 2:33 a.m. HST
- Daily Update · Dec 24, 2025, 9:25 a.m. HST
Daily updates: USGS Kīlauea volcano updates. Full table: USGS Timeline of Eruptive Episodes.
Times are Hawaiʻi-Aleutian Standard Time (HST). Start and pause times, durations, fountain heights and lava volumes come from the USGS Hawaiian Volcano Observatory's Timeline of Eruptive Episodes; tilt figures and episodes not yet in that table are quoted from HVO notices. USGS describes these as unreviewed, preliminary estimates that are subject to revision. Durations for episodes 17 and earlier may include precursory activity, and HVO rounds durations to the nearest hour, half-hour or day. A blank cell means HVO hasn't published that figure in a form we could read; we don't estimate it.
Credit: U.S. Geological Survey. This archive is generated automatically and is not an official USGS product.