Measured by how often they actually erupt, the most volcanic islands in the world today are Hawaiʻi Island, Iceland and Java. On Hawaiʻi Island, Kīlauea erupted 61 times between 1823 and 2024 and Mauna Loa returned in 2022. Iceland has around 30 active volcanic systems and saw 12 eruptions on its Reykjanes Peninsula alone between 2021 and 2025. Java has 112 volcanoes, 35 of them active, including Merapi. Twenty or thirty years ago the list looked different. Hawaiʻi still led, but Montserrat in the Caribbean was the island everyone watched, the Reykjanes Peninsula had been quiet for about 800 years, and islands such as La Palma and Hunga Tonga were not on anyone's shortlist.
Counting eruptions, not mountains: how this list is built
"Most volcanic" can mean two different things. One is the number of volcanoes on an island, a measure that favours long, old island arcs such as Java or Honshu. The other is how much is actually happening: how many eruptions, how much lava, and how often people have to be evacuated.
This article uses both. The table lists ten islands that have been the most active since the mid-1990s, with the eruptions that defined each one then and now. Figures come from each volcano's and eruption's Wikipedia article, which draw on national monitoring agencies such as the USGS Hawaiian Volcano Observatory and the Icelandic Meteorological Office. There is no single official ranking of islands by volcanic activity, so the order is a judgement based on eruption frequency and volume, not a count from one database.
| Rank | Island | Country | Main volcanoes | 1990s to 2007 | Since 2010 |
|---|---|---|---|---|---|
| 1 | Hawaiʻi Island | United States | Kīlauea, Mauna Loa | Puʻu ʻŌʻō eruption, continuous since 1983 | 2018 lower Puna eruption; Mauna Loa 2022; Halemaʻumaʻu fountains from December 2024 |
| 2 | Iceland | Iceland | Bárðarbunga, Reykjanes systems | Reykjanes Peninsula quiet for centuries | Eyjafjallajökull 2010; Holuhraun 2014–15; 12 Reykjanes eruptions 2021–25 |
| 3 | Java | Indonesia | Merapi, Semeru | Merapi 1994 (27 killed) and 2006 | Merapi 2010 (353–386 killed); 35 active volcanoes |
| 4 | Sicily | Italy | Etna | Flank eruptions 2001, 2002–03, 2004–05 | Summit eruptions 2018, 2021, 2024 |
| 5 | Réunion | France | Piton de la Fournaise | April 2007 eruption and Dolomieu crater collapse | Still among the world's most active; more than 150 recorded eruptions |
| 6 | Sumatra | Indonesia | Sinabung | No dated eruption since 740–880 CE | Sinabung active from 2010; major eruption 2020 |
| 7 | Anak Krakatau | Indonesia | Anak Krakatau | Sporadic eruptions since the late 20th century | Flank collapse and tsunami, December 2018; eruption September 2026 |
| 8 | La Palma | Spain | Cumbre Vieja | Quiet since Teneguía, 1971 | 85-day eruption, September–December 2021 |
| 9 | Nishinoshima | Japan | Nishinoshima | Quiet since 1974 | Island enlarged by eruptions from 2013 to 2020 |
| 10 | Montserrat | United Kingdom (overseas territory) | Soufrière Hills | Erupting from July 1995 | Eruption ended 2010; last activity 2013 |
The 1995–2005 leaders: Kīlauea, Montserrat and Etna
In the late 1990s the most volcanic island on Earth was not in doubt. On Hawaiʻi Island, the Puʻu ʻŌʻō eruption on Kīlauea's East Rift Zone had begun on 3 January 1983 and was still going. By January 2005 it had covered more than 117 km² with lava, destroyed at least 189 buildings and 14 km of highway, and added about 230 acres of new land to the island's south-east coast.
The island that drew most of the world's attention, though, was Montserrat. The Soufrière Hills volcano woke on 18 July 1995 after a long dormancy. Pyroclastic flows followed from March 1996, and on 3 April 1996 southern Montserrat, including the capital Plymouth, was permanently evacuated. On 25 June 1997 a large eruption killed 19 people and destroyed the island's airport, and by August 1997 most of Plymouth had been buried. More than half the island became uninhabitable, and about two-thirds of the population left.
In Sicily, Mount Etna had six years of unusually intense summit activity from 1995 to 2001, with as many as 16 eruptions in 2001 alone. Its July–August 2001 flank eruption, from seven fissures on the south slope, damaged the Etna Sud tourist area, and further flank eruptions followed in 2002–03 and 2004–05. On Java, Merapi killed 27 people with a pyroclastic flow on 22 November 1994, mostly in the town of Muntilan, and erupted again in 2006. Réunion's Piton de la Fournaise, with more than 150 recorded eruptions since the 17th century, closed the period with its large April 2007 eruption, which poured out about 3 million cubic metres of lava a day as the floor of its Dolomieu crater dropped 330 m.
Iceland's climb: Eyjafjallajökull in 2010 to Grindavík in 2025
No island has risen further in the ranking than Iceland. It was always volcanic: it sits on the Mid-Atlantic Ridge above a hotspot, has around 30 active volcanic systems, and nearly thirty volcanoes have erupted there since the end of the last ice age. What changed was the frequency and the visibility of its eruptions.
The first sign was Eyjafjallajökull. Between 14 and 20 April 2010 its ash spread across northern Europe, about 20 countries closed their airspace, and roughly 10 million travellers were affected. Four years later Bárðarbunga produced a much larger but less disruptive event: the Holuhraun fissure eruption, from 29 August 2014 to 27 February 2015, released huge amounts of sulphur dioxide but little ash.
The biggest shift came on the Reykjanes Peninsula, about 40 km from Reykjavík. No eruption had occurred there for about 815 years until a fissure opened at Fagradalsfjall on 19 March 2021. Further eruptions followed in August 2022 and July 2023. Then, after an earthquake swarm that led to the evacuation of the fishing town of Grindavík on 10 November 2023, the Sundhnúkur crater row erupted on 18 December 2023. Eight more eruptions followed by August 2025. The second, on 14 January 2024, opened a fissure less than 100 m from Grindavík and destroyed three homes; the third, on 8 February 2024, cut the hot-water pipeline from the Svartsengi power station; the fourth, from 16 March 2024, lasted 54 days.
Twelve eruptions in five years on one peninsula, close to the capital and the international airport at Keflavík, is why Iceland now sits second on this list rather than somewhere in the middle.
Hawaiʻi Island after 2018: Leilani Estates, Mauna Loa and Halemaʻumaʻu
Hawaiʻi Island kept first place, but the shape of its activity changed. On 3 May 2018 fissures opened in the Leilani Estates subdivision of lower Puna. By 27 May, 24 fissures had erupted; about 2,000 residents were evacuated, lava filled Kapoho Bay and boiled away Green Lake, Hawaiʻi's largest natural freshwater lake, and some 700 homes were destroyed. It was the most destructive volcanic activity in the United States since Mount St. Helens in 1980. The Puʻu ʻŌʻō eruption, which had begun in 1983, ended that year.
The island then did something new. In July 2019 a water lake appeared in Halemaʻumaʻu crater at Kīlauea's summit for the first time in more than 200 years; on 20 December 2020 an eruption boiled it off and replaced it with a lava lake. Mauna Loa, the world's largest active volcano, erupted from 27 November to 10 December 2022, its first eruption in 38 years and the longest quiet spell in its record since 1843, and for the first time since 1984 both volcanoes were erupting at once. The latest Kīlauea eruption, which began in Halemaʻumaʻu in December 2024, has produced episodic lava fountains that were still continuing in 2026.
Java, Sumatra and Anak Krakatau: Indonesia's islands move up
Indonesia's islands hold their places mainly through their sheer number of volcanoes. Java is almost entirely volcanic: of its 112 volcanoes, 35 are active, the highest being Semeru at 3,676 m and the most active Merapi at 2,930 m. In late October and November 2010 Merapi had its largest eruption since 1872. More than 350,000 people were evacuated and between 353 and 386 were killed, many by pyroclastic flows on the heavily populated slopes north of Yogyakarta.
Sumatra moved up because a long-quiet volcano came back to life. Mount Sinabung, 40 km from Lake Toba in the Karo highlands, had no well-dated eruption since one placed between 740 and 880 CE, about 1,200 years earlier. It erupted on 29 August 2010, again repeatedly from 2013, and in a major eruption on 10 August 2020; since 2014 it has killed at least 23 people.
The most dramatic Indonesian event of the period came from the island of Anak Krakatau in the Sunda Strait, whose name means "child of Krakatoa" and which first emerged in 1927 from the caldera left by the 1883 eruption. On 22 December 2018 a large part of its south-western flank collapsed into the sea. The resulting tsunami struck the coasts of Banten and Lampung at night, without warning, and killed more than 420 people (426 in one tally, 437 in the disaster agency's count of 31 December), the deadliest volcanic tsunami in Indonesia since 1883.
Who fell, who arrived: Montserrat, La Palma, Hunga Tonga and Nishinoshima
Montserrat is the clearest faller. The Soufrière Hills volcano continued to erupt until 2010 and last erupted in 2013. More than half of the island, including the ruins of Plymouth, remains uninhabitable, but the volcano is no longer among the world's most active.
The newcomers are mostly small islands. On La Palma in the Canary Islands, the Cumbre Vieja ridge erupted from 19 September to 13 December 2021, the island's first eruption since Teneguía in 1971. In 85 days its lava covered more than 1,000 hectares, destroyed more than 3,000 buildings including the town of Todoque, forced about 7,000 people to evacuate and caused damage estimated at up to €843 million.
In Tonga, the twin islands of Hunga Tonga and Hunga Haʻapai had been joined into one by a new volcanic cone in 2014–15. On 15 January 2022 the underlying submarine volcano produced at least a VEI 5 eruption, the largest atmospheric explosion ever recorded by modern instruments and the largest eruption anywhere since Pinatubo in 1991. It split the islands apart again and sent tsunami waves as far as Peru, where two people drowned.
Japan's Nishinoshima, about 940 km south-south-east of Tokyo, shows the opposite: an island being built rather than destroyed. An eruption that began in November 2013 swallowed the old island, further eruptions followed in 2017, 2018 and 2019–20, and by August 2020 it covered about 4.1 km².
Four decades on, Hawaiʻi still leads, Iceland has climbed since 2010, Indonesia's islands rank high on sheer numbers of volcanoes, and Montserrat has dropped out. For the story of Hawaiʻi's most active volcano, read our guide to Kīlauea; our ranking of countries with the most active volcanoes takes the comparison from single islands to whole nations, and our Krakatoa guide traces Anak Krakatau's story back to the 1883 explosion.