Rincón de la Vieja has overtaken Turrialba and Poás as Costa Rica’s most active volcano, vulcanologists at the National University said this week, after three eruptions in 10 days culminated in the most energetic event recorded at the Guanacaste massif so far this year.
The 1,916-meter volcano erupted at 3:03 a.m. last Monday, April 27, in a moderate event that the Volcanological and Seismological Observatory of Costa Rica (OVSICORI-UNA) described as the strongest at the site since January. Seismic and acoustic instruments registered the eruption, but darkness prevented monitoring cameras from measuring the height of the plume. No lahars, the volcanic mudflows that pose the greatest risk to surrounding communities, were generated.
“The conduct of the volcano changed in recent weeks,” OVSICORI vulcanologist Geoffroy Avard told local media, describing a return to a more eruptive phase after a quieter stretch earlier in 2026. Several low-intensity eruptions are now being recorded each week.
The April 27 event was preceded by a 12:08 p.m. eruption on April 17 that registered a magnitude of 3.8 and sent a dense column of gas and ash above the crater, and a separate eruption on April 24 that produced a gas plume reaching 1,500 meters. Each was briefly described as the strongest of the year before being surpassed.
OVSICORI vulcanologist Henriette Bakkar said the recent activity has been phreatic — driven by interaction between groundwater and the volcano’s heat — rather than magmatic. The material being expelled consists of crater-lake sediments and steam, she said, and lava emission has been ruled out for now. Bakkar told Costa Rican broadcaster Monumental that despite the recent intensity, the events remain considerably smaller than eruptions registered in 2021 and 2023.
The aviation alert level for Rincón de la Vieja remains at Yellow, the second of four levels, according to OVSICORI bulletins.
Park access and visitor guidance
Rincón de la Vieja National Park, part of the UNESCO-listed Guanacaste Conservation Area, sits about 25 kilometers northeast of Liberia and is one of the region’s most-visited destinations. The park’s two sectors, Las Pailas and Santa María, remain open to visitors, with trails leading to fumaroles, boiling mud pots, hot springs, and the La Cangreja and Las Escondidas waterfalls. The Sendero Crater Activo, the trail to the active crater itself, has been closed since 2011 and remains off limits.
The National Emergency Commission (CNE) has previously advised residents in communities near the volcano to stay away from riverbeds that could carry volcanic sediment during periods of heightened activity. Travelers staying in Liberia, the Papagayo Peninsula, or Rincón-area lodges are urged to confirm park status with SINAC or their tour operator before visiting and to monitor OVSICORI updates for ash advisories.
