Hawaiian Volcano Update: Still Waiting for Kīlauea Summit Eruption’s Episode 31 - August 21, 2025

Kīlauea’s 31st episode is now expected within the next 2 to 6 days, with persistent strong glow and occasional spatter evident at the north vent. Similar to the build-up ahead of episode 30, the volcano’s inflation rate stagnated for several days after recovering from its outburst, extending the length of its pause and increasing the possibility of new fissures. 

USGS Hawaiian Volcano Observatory reports suggest that variations in magma supply may be partly to blame for the slowdown in pressure build-up, as well as the growing bulk of the vent requiring greater pressure to erupt. This increases the possibility that magma could inject into other “weak areas of the surrounding summit” and possibily “result in permanent change in the vent locations or eruptive behavior” such as episode 30’s new fissure which reached the southern caldera wall.  However, they go on to state that “currently, there are no indications that any eruptive activity would occur outside of the summit region. Kīlauea’s East Rift Zone continues to contract, indicating no magma is entering that part of the system.”

As with every summit eruption in the last 5 years, vog and tephra remain the most common hazards for island residents, and the usual precautions and preparations apply, especially for those with respiratory sensitivities – more information at https://vog.ivhhn.org/. All eruptive activity has been confined to Kīlauea’s summit caldera within Hawaiʻi Volcanoes National Park, with no increased lava threat to people. There continue to be no significant changes on either of Kīlauea’s rift zones.

Maunaloa continues to inflate its established post-eruption pattern, with localized adjustments increasingly evident on monitoring instruments in recent weeks, perhaps coincident with pressure changes at Kīlauea. As usual, we summarize the monitoring signals, imagery, and reports available courtesy of the USGS Hawaiian Volcano Observatory, annotating the presentation on screen as we go and discussing live viewer questions. 

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