Reykjanes Eruptions Explained (2021–2025): Fagradalsfjall vs. Grindavík/Svartsengi, What’s Happening Now, and How to Stay Safe

Last updated: 18 December 2025

The Reykjanes Peninsula in Southwest Iceland has entered a renewed period of volcanic activity after centuries of relative quiet. Since 2021, eruptions have occurred in two nearby but distinct volcanic settings that matter a lot for travelers:

• Fagradalsfjall (2021–2023): generally more “visitor-friendly” eruption locations (still hazardous, but typically farther from critical infrastructure).
• Svartsengi/Sundhnúkur–Grindavík (late 2023–2025): eruptions and magma intrusions much closer to the town of Grindavík and major infrastructure like the Svartsengi area, requiring stricter closures and safety controls.

This guide explains the difference, provides a clear timeline, summarizes what the official monitoring shows right now (as of 18 December 2025), and outlines what travelers should and should not do.

As of 18 December 2025, the Svartsengi system remains in a period of increased likelihood of a new magma intrusion and eruption. The Icelandic Meteorological Office (IMO) states that an eruption may occur at any time after the lower “magma volume” threshold is reached, and it also emphasizes that timing is uncertain and that a short-term forecast is issued when monitoring detects signals of dike propagation.

IMO’s modeling indicates magma has been accumulating beneath Svartsengi since the last eruption in July 2025, and that the “increased likelihood” window began in late September 2025. The same IMO update stresses that an eruption could occur with limited warning once the system accelerates.

1) Fagradalsfjall chapter (2021–2023): dikes and eruptions in a relatively less infrastructure-dense area

The ongoing Reykjanes activity period began with magma movement and dike intrusions around Fagradalsfjall, producing eruptions that ran from March 2021 through the later events in 2022 and 2023. IMO’s overview notes that between February 2021 and August 2023 there were multiple dike intrusions and three eruptions in the Fagradalsfjall area. These eruptions are what Icelanders jokingly like to call "tourist eruptions" were rather tame and a lot of people hiked up to the lava for fun.

Key traveler takeaway: these eruptions were often treated more like “remote nature hazards” (gas, lava, terrain risk) rather than direct threats to a populated town’s footprint—although closures and air-quality impacts still occurred.

2) Svartsengi/Grindavík chapter (late 2023–2025): magma intrusions and eruptions close to town and critical infrastructure

From late 2023 onward, the most consequential activity shifted toward the Svartsengi area and the Sundhnúkur crater row near Grindavík. IMO describes how magma accumulation in this system contributed to a major dike intrusion in November 2023 in the Grindavík/Svartsengi area, creating significant seismic risk near inhabited areas and infrastructure. These eruptions have been more volatile and definitely not "tourist eruptions" due to their location, gas emissions etc.

Key traveler takeaway: this chapter is managed with stricter access controls, fencing, evacuation readiness, and highly dynamic closures. Even after an eruption ends, the area can remain dangerous due to unstable ground and fractures. Grindavík was evacuated and only a handful of inhabitants have returned.

Fagradalsfjall era

• 19 March 2021: Eruption begins near Fagradalsfjall (Geldingadalur).
• 3 August 2022: Meradalir eruption begins; IMO reports the eruption commenced on 3 August and stopped issuing lava on 21 August 2022.
• 10 July 2023: A new eruption begins near Litli-Hrútur (northwest of the prior sites).

Svartsengi / Sundhnúkur–Grindavík era

• Late 2023: Major dike intrusion and evacuation risk near Grindavík; the area enters a repeated-event phase.
• 16 July 2025: Eruption begins on the Sundhnúkur crater row; later confirmed ended in early August 2025 by IMO.

• Magma is accumulating beneath Svartsengi.
• Once modeled thresholds are reached, the probability of a new intrusion and eruption rises.
• Timing remains uncertain. No responsible source can promise a precise day or week.
• Short-term warnings come when signals of dike propagation appear.

The honest traveler message is: the system can escalate quickly. Most likely you will not encounter any closure of roads, airports etc, and our staff will guide you if that is the case, but if we've learned anything from the past few eruptions, this next one should not alter your travel plans in any major way.

Do

• Follow official updates daily when traveling in Reykjanes (IMO + Civil Protection).
• Respect all closures, fencing, and “safe area” markings.
• Be ready to change plans quickly if conditions shift.
• Check roads and closures before you drive, especially on the Reykjanes Peninsula.

Do not

• Do not enter restricted zones “just for a look.” Ground fractures and unstable terrain can be invisible and dangerous.
• Do not rely on social media rumors for eruption timing or “secret viewpoints.”
• Do not assume “eruption ended” means “area is safe.” Gas and unstable ground can remain hazardous.

If you are staying in Reykjavík

Most events do not disrupt Reykjavík daily life, but they may possibly cause:

• temporary closures of specific roads and areas on Reykjanes,
• air-quality advisories depending on wind direction,
• dynamic access restrictions near the hazard zone.

If you are flying in/out of Keflavík (KEF)

These fissure eruptions often have limited ash impact compared to explosive eruptions, but every event is different. Monitor official updates if activity increases during your travel window.

If you want to visit Reykjanes

Assume plans may change quickly. If you drive there, keep your schedule flexible, do not chase “live lava,” and treat closures as non-negotiable.

The Reykjanes Peninsula’s recent eruptions are best understood as two linked but distinct chapters: Fagradalsfjall (2021–2023) and Svartsengi/Grindavík (late 2023–2025). As of 18 December 2025, Svartsengi remains in an elevated likelihood phase for renewed activity, with uncertain timing and the possibility of rapid escalation. Travel safely by staying flexible, following official guidance, and respecting all closures.