Costa Rica has 11 volcanoes in our database with 104 eruptions recorded — packed into a country smaller than West Virginia. Two are currently at Alert Level 2 after Poás erupted in April 2025 with a 4.5 km ash plume. Arenal's 1968 eruption killed 87 people and transformed the country's approach to volcano monitoring. Today, volcano tourism is central to Costa Rica's economy — few places on Earth put you this close to active volcanism, hot springs, and tropical rainforest in one visit.
By VolcanoDB Research Team. Data: Smithsonian Global Volcanism Program, OVSICORI-UNA (Costa Rica Volcano Observatory).
Volcanoes in DB
11
Recorded Eruptions
104
At Alert Level 2
2
Last Eruption
2025
Why Costa Rica Has So Many Volcanoes
Costa Rica sits on one of the most volcanically active plate boundaries on the planet. The Cocos Plate — a chunk of Pacific oceanic crust — dives beneath the Caribbean Plate at about 8 cm per year along the Middle America Trench off the Pacific coast. As the subducting plate descends, water released from the slab lowers the melting point of the overlying mantle, generating magma that feeds the Central American Volcanic Arc.
This arc runs from Guatemala to Panama, and Costa Rica's portion — roughly 200 km from the Nicaraguan border to the Turrialba region — packs 11 volcanic centers into a compact corridor. It's part of the Pacific Ring of Fire, the same tectonic system that produces the Philippines' 51 volcanoes and Japan's 142. But Costa Rica's volcanoes are special: they're accessible, well-monitored, and surrounded by some of the richest biodiversity on Earth.
Active Volcanoes in Costa Rica (2026 Status)
OVSICORI (Observatorio Vulcanológico y Sismológico de Costa Rica) monitors all volcanic activity in the country. As of 2026, two volcanoes are at elevated alert levels, and three more are considered active based on recent eruption history.
Poás is the most volatile of Costa Rica's volcanoes right now. Its crater lake — one of the most acidic bodies of water on the planet, with a pH hovering near zero — sits atop a pressurized hydrothermal system that periodically blows. The most dramatic event in recent memory was April 21, 2025, when an eruption sent an ash plume 4.5 km into the sky. The Red Alert closure lasted months. Eruptions continued into early 2026. Our database records 20 eruptions at Poás, but the phreatic events (steam-driven explosions) happen far more frequently than that — dozens of smaller events go unrecorded.
Turrialba — Alert Level 2 (Active)
Turrialba woke up in 2014 after more than a century of quiet, and it's been grumbling ever since. Periodic ash emissions have repeatedly dusted San José — Costa Rica's capital, just 35 km away — forcing school closures and disrupting flights at Juan Santamaría International Airport. The activity has been intermittent: sometimes months of quiet, then a burst of ash and gas. OVSICORI maintains Alert Level 2 as of 2026. Our database records 20 eruptions dating back to 1723. When open, the summit offers views into three craters.
Arenal — Resting (Since 2010)
Arenal is Costa Rica's most famous volcano and one of the most devastating in Central American history. On July 29, 1968, at 7:30 AM, it erupted without warning after an estimated 500 years of dormancy. The explosion — a lateral blast reminiscent of what would happen at Mount St. Helens 12 years later — killed 87 people and buried the villages of Tabacón, Pueblo Nuevo, and San Luís under pyroclastic flows and lahars. It then erupted continuously for 42 years — one of the longest sustained eruptions in modern history.
In October 2010, Arenal went quiet. Faint wisps of steam still rise from the summit, but there's been no significant eruptive activity in 16 years. Volcanologists caution that Arenal is dormant, not extinct — the 1968 eruption proved the volcano can restart explosively after centuries of silence. The 1968 disaster was the catalyst for establishing OVSICORI, Costa Rica's national volcano observatory.
Irazú — Costa Rica's Highest Volcano
At 11,273 feet, Irazú towers over the Central Valley. Its defining moment came on March 13, 1963, when it erupted during President John F. Kennedy's state visit to Costa Rica. Ash rained on the presidential motorcade in San José. The eruption continued for nearly three years, covering farms with centimeters of ash and devastating the coffee and dairy industries of the Central Valley. Our database records 20 eruptions dating back to 1723. The most recent activity was a small phreatic eruption in December 1994.
Rincón de la Vieja — The Underrated One
Rincón de la Vieja doesn't get the tourist traffic of Arenal or Poás, but it might be the most interesting volcano in the country. It's a sprawling complex with 9 craters, the most active of which holds a hot, acidic lake. Phreatic eruptions occur multiple times per year — the Smithsonian recorded 20 events in our database, with the most recent confirmed in 2021. These eruptions sometimes produce lahars that rush down the volcano's flanks into rivers. The lower slopes are a geothermal wonderland: mud pots, fumaroles, hot springs, and the famous Río Celeste (which isn't from this volcano, but the adjacent Tenorio — a common misconception). Our database has 20 eruptions, the last confirmed in 2021.
Juan Santamaría Airport closed. Schools suspended.
The Arenal disaster transformed Costa Rica's approach to volcano risk. Before 1968, there was no systematic monitoring. The 87 deaths — many from families who didn't know they lived near an active volcano — led directly to the establishment of OVSICORI in 1974. Today, every major volcano has seismometers, gas sensors, and GPS deformation monitoring. Compare this to the deadliest volcanic eruptions in history, where lack of monitoring was the common thread.
Visiting Costa Rica's Volcanoes
Costa Rica is one of the best places in the world for volcano tourism. Four national parks protect the major volcanoes, all with good infrastructure and English-speaking guides. Park entry is a standard $15 for foreign adults across all volcano parks. The dry season (December to April) gives the best visibility, but volcanoes are dramatic year-round.
Arenal is the reason most people visit Costa Rica's volcano country. The near-perfect cone towers over La Fortuna, and even though it hasn't erupted since 2010, the volcano is far from boring. Trails through hardened lava flows from the 1968 eruption give you a visceral sense of the volcano's destructive power — you're walking on rock that buried three villages and killed 87 people. The real draw, though, is the hot springs. Tabacón, heated by volcanic geothermal activity, has thermal pools ranging from warm to genuinely hot, set in tropical gardens. Budget alternative: Baldi Hot Springs has 25 pools at lower prices. Combo tours from San José run about $179 and include the volcano hike, waterfall, and hot springs with lunch.
Entry & Tours
$15 USD park entry (adults), $5 (children). Hot springs: $45-99 separate. Combo tours from San José: ~$179.
Best Time
December to April (dry season). Morning visits for clearest volcano views — clouds roll in by afternoon.
Poás gives you what almost no other volcano on Earth can: a drive-up view directly into an active crater lake. The hyperacidic lake (pH near 0) changes color from turquoise to green to gray depending on activity. A 10-minute paved trail leads from the parking lot to the crater viewpoint. The catch: Poás has been erupting periodically since 2017, and the April 2025 eruption sent a 4.5 km ash plume, triggering a Red Alert closure for months. The park reopens with strict protocols — visits are limited to 40 minutes, advance reservations required through the SINAC website, and no more than 50 people at the crater rim at once. Check OVSICORI status before planning.
At 11,273 feet, Irazú is the highest point you can drive to in Costa Rica. On clear mornings — and 'clear' is doing heavy lifting here, because clouds close in fast — you can see both the Atlantic and Pacific oceans from the summit. The main crater holds a green lake that shifts color with temperature and chemistry. The Diego de la Haya crater nearby is dry. What makes Irazú special is the history: the 1963-1965 eruption rained ash on San José for nearly three years, destroying agriculture across the Central Valley. It started during JFK's state visit, coating the presidential motorcade in volcanic dust.
Entry & Tours
$15 USD entry (adults), $5 (children). No reservation needed.
Best Time
Arrive before 10 AM — clouds cover the summit by late morning almost every day. Best visibility: December-March dry season.
The most adventurous of Costa Rica's volcano parks. Rincón de la Vieja is a sprawling complex volcano with bubbling mud pots, hissing fumaroles, hot rivers, and multiple waterfalls — like a mini Yellowstone in the tropics. The Las Pailas trail loops through the most concentrated geothermal area: miniature mud volcanoes, sulfur vents, and a volcanic hot spring river. The Catarata La Cangreja waterfall (a 5 km hike each way) plunges into a pool with naturally blue-tinted water. Phreatic eruptions happen regularly but typically affect only the summit crater, not the lower trails.
Dry season (December-April). Trails can be muddy and slippery in rainy season. Check OVSICORI — summit area closes during eruptions.
Frequently Asked Questions
How many volcanoes does Costa Rica have?
Costa Rica has 11 volcanoes in our database with 104 total eruptions recorded. The country has over 200 volcanic formations including extinct cones and eroded remnants, but the Smithsonian Global Volcanism Program tracks 10 Holocene volcanoes (erupted in the last 10,000 years). Five are currently considered active: Poás, Turrialba, Rincón de la Vieja, Arenal, and Irazú. All sit along the Central American Volcanic Arc where the Cocos Plate subducts beneath the Caribbean Plate.
Which Costa Rica volcanoes are active in 2026?
As of 2026, Poás and Turrialba are at Alert Level 2 (Warning) from OVSICORI, Costa Rica's volcano observatory. Poás erupted in April 2025, sending ash 4.5 km high and triggering a Red Alert. Turrialba has been in a state of unrest since 2014 with periodic ash emissions reaching San José. Rincón de la Vieja has frequent phreatic (steam-driven) eruptions. Arenal, Costa Rica's most famous volcano, has been in a resting phase since 2010 after 42 years of continuous eruption (1968-2010). Irazú last erupted in 1994.
Can you hike Arenal Volcano?
You can hike trails in Arenal Volcano National Park, including paths through solidified lava flows from the 1968 eruption, but you cannot climb to the summit. The upper slopes are off-limits because the volcano could resume erupting at any time — Arenal erupted continuously for 42 years (1968-2010) and is considered dormant, not extinct. The park trails, hanging bridges, and nearby La Fortuna Waterfall are excellent alternatives. Combine with Tabacón or Baldi hot springs for a full-day experience.
Is Poás Volcano open to visitors in 2026?
Poás Volcano National Park has reopened with strict safety protocols after the April 2025 eruption. Visits are limited to 40 minutes at the crater rim, with a maximum of 50 visitors at a time. Advance reservations are required through the SINAC website ($15 USD adults, $5 children). However, OVSICORI maintains an Alert Level 2 (Warning), and the park can close without notice if activity increases. Always check the current status at OVSICORI's website before visiting.
What is the most dangerous volcano in Costa Rica?
Historically, Arenal. Its July 29, 1968 eruption killed 87 people and buried three villages (Tabacón, Pueblo Nuevo, and San Luís). It was unexpected — the volcano had been dormant for centuries and wasn't recognized as a significant threat. Today, Poás and Turrialba cause the most frequent disruptions with phreatic eruptions and ashfall on San José and the Central Valley. Irazú's 1963-1965 eruption caused the most widespread economic damage, raining ash on the capital for nearly three years.
Is it safe to visit volcanoes in Costa Rica?
Yes, with proper precautions. Costa Rica has excellent volcano monitoring through OVSICORI (Observatorio Vulcanológico y Sismológico de Costa Rica), established after the 1968 Arenal disaster. National parks have trained guides and established evacuation protocols. Stick to official trails, obey park closures, and check OVSICORI alerts before visiting Poás or Turrialba. The hot springs near Arenal are completely safe — the geothermal heating happens far underground.