Storm Therese Floods Canary Islands, Triggers Evacuations and School Closures

The first warning came not from the sky but from the loudspeakers.

In the hillside hamlets of Los Pérez and El Hornillo, above the town of Agaete on Gran Canaria, local police went door to door on March 21 telling residents to leave. Days of rain had swollen the reservoir above them, and authorities feared the dam could spill. Within hours, families were moved out as mud-brown water roared through nearby ravines.

By then, the slow-moving Atlantic storm that forecasters had named Therese had already grounded flights, shut ports, closed beaches and flooded homes across much of the Canary Islands.

Therese, a deep low-pressure system classified by meteorologists as a borrasca fría aislada—a cold-core cut-off low—settled over the subtropical archipelago in the second half of March. From March 19 to 21, it delivered intense, persistent rain, gale-force winds, waves more than four meters high and rare late-season snow on Mount Teide.

The storm’s impact fell overwhelmingly on the islands rather than the Spanish mainland. It also arrived at the end of what national forecasters describe as an extraordinary winter: 19 named high-impact storms since autumn and rainfall about 42% above normal across Spain. Early scientific analyses suggest that human-driven climate change has already made such downpours measurably heavier.

Days under warning

Portugal’s meteorological agency, IPMA, named Storm Therese on March 16 under a joint South-West Europe protocol used with Spain’s AEMET, Météo-France and Belgium’s royal weather service. Only storms expected to bring at least orange-level impacts on the agencies’ color-coded warning scale receive names.

“Solo se bautizan las borrascas que, en principio, dejarán impactos importantes,” AEMET and radio outlets reminded audiences—only the potentially high-impact storms are “baptized.”

AEMET issued special advisories for the Canary Islands as early as March 18. Forecasters warned that a slow, quasi-stationary low west of the islands would funnel moist southwesterly winds over the archipelago for days.

“It is going to be a temporal de viento, lluvia y mala mar,” AEMET spokesperson Rubén del Campo said in a televised forecast, referring to a prolonged episode of wind, rain and rough seas. He cautioned that some windward slopes of La Palma and Tenerife could see more than 300 liters of rain per square meter and that “los barrancos podrían bajar con mucha agua,” meaning ravines could suddenly fill with torrents.

Regional and island authorities moved quickly. The Canary Islands government activated its emergency plan for adverse meteorological phenomena, known by its Spanish acronym PEFMA, covering rain, wind and coastal hazards. Island emergency plans were triggered in Tenerife and Lanzarote, giving local officials authority to close roads, suspend activities and coordinate civil protection.

On March 18, the regional Education Department suspended in-person classes for March 19 in much of the province of Santa Cruz de Tenerife and on La Graciosa. All schools across the archipelago shifted to remote instruction on March 20. The University of La Laguna on Tenerife also halted in-person activity.

Ports in Arrecife on Lanzarote and Puerto del Rosario on Fuerteventura were temporarily closed, and municipalities from Arrecife to Tías shut public facilities and canceled outdoor events. Grassroots and regional football matches in Tenerife were called off for the weekend.

Flooded homes, closed beaches and snow on Teide

Rain intensified on March 19 and 20, particularly over the western islands. Orographic uplift on the volcanic slopes squeezed more water from the saturated air.

By March 21, a rainfall station at Cruz de Tea, in the municipality of Granadilla de Abona on Tenerife, had recorded 212 millimeters. Forecasters reported widespread heavy rain, thunderstorms and, in some pockets, hail.

The downpours caused flash flooding in several low-lying towns on Tenerife’s north and south coasts, including Buenavista del Norte, El Médano and Los Silos. Images from local authorities showed brown water flowing through streets and into ground-floor homes, while civil protection teams cleared mud and debris.

On mountain roads, rockfalls and small landslides forced closures. Access routes to Teide National Park were shut as snow accumulated at higher elevations. Authorities reported 10 to 20 centimeters of fresh snow on the summit, an unusual late-March scene that drew interest but also posed risks on icy roads.

The sea, meanwhile, turned dangerous. With the storm’s low pressure and strong winds piling up swell from the northwest, wave buoys and emergency bulletins recorded combined seas above four meters across much of the archipelago. In more exposed stretches around Lanzarote and Fuerteventura, officials warned of possible peaks of five to six meters or more.

Beachfront areas in the south of Gran Canaria, including Arguineguín, were closed as surf crashed over promenades and washed debris onto the sand. Authorities urged people to stay away from jetties and coastal paths.

The maritime conditions disrupted ferry traffic even as air links faltered. On March 21 alone, at least 24 flights were canceled and three diverted at Canary airports, with La Palma hit hardest. Cancellations affected services between La Palma and Tenerife and Gran Canaria, as well as flights to and from Madrid, Düsseldorf and Faro.

Passengers in La Palma described staying overnight at the airport or being told to consider traveling by sea despite the rough conditions.

Mainland sees showers, not catastrophe

By the weekend, Therese’s influence began to extend into southern mainland Spain, but its punch was far weaker there.

Cloudier skies, cooler temperatures and scattered showers were reported across Andalusia and parts of the eastern and southeastern coast. AEMET noted that instability linked to the storm would bring some rain to the Mediterranean and Balearic Islands as well.

There were no reports of major flooding or damage in mainland Spain tied directly to Therese. February’s Storm Leonardo and the subsequent floods around Grazalema in Cádiz province remained the season’s benchmark for extreme rainfall on the peninsula.

The contrast underscored how strongly Therese had been focused on the Atlantic-facing Canary Islands, whose steep terrain and dense coastal development magnified the storm’s effects.

Part of a record storm train

Therese arrived in a winter already shaped by a “tren de borrascas,” or train of storms, crossing the Iberian Peninsula and surrounding waters since autumn 2025.

By mid-March, AEMET and partner agencies had named 19 “borrascas de gran impacto,” high-impact storms that reached at least orange warning level. That figure surpassed Spain’s previous record of 17 named storms in a season.

Hydrological data released in late February indicated that accumulated rainfall since the start of the water year was about 42% above the long-term average, roughly 460 millimeters compared with an expected 323 millimeters. Reservoirs that had been depleted by several dry years saw significant inflows.

A scientific attribution study published in late February found that rainfall associated with the storm train since mid-January was up to 11% more intense because of global warming caused by greenhouse gas emissions. While the research did not isolate Therese specifically, it placed the season’s extremes in a broader context of a warming atmosphere that can hold and release more moisture.

Recent years have also brought other high-impact storms to the Canaries. In December 2025, Storm Emilia lashed the islands with hurricane-force gusts and waves reportedly exceeding nine meters, triggering more than 2,000 emergency incidents. Historical accounts recall catastrophic floods such as the 1957 tragedy in La Palma, which killed dozens.

Meteorologists caution that extreme rainfall and coastal storms are not new to the region, but say the combination of more frequent high-impact lows, higher sea levels and greater exposure—through growing populations, tourism infrastructure and development in ravines—is raising the stakes.

Testing preparedness on the Atlantic edge

In the case of Therese, officials say early activation of emergency plans, school closures and preventive evacuations contributed to the absence of reported fatalities.

The Canary Islands’ PEFMA protocol and island-level emergency plans allowed authorities to restrict access to risk zones, from mountain roads to exposed beaches. Civil protection teams evacuated residents in vulnerable neighborhoods near dams, rescued at least one elderly man cut off by floodwaters in Gáldar and monitored critical infrastructure.

At the same time, the storm highlighted persistent vulnerabilities. Elderly and isolated residents remained at risk in narrow valleys where warning time can be short. On islands with limited transport corridors, the closure of a single airport or mountain road can cut off communities. Tourism-dependent economies feel immediate losses when flights are canceled and flagship events like the Maspalomas Carnival parade are postponed.

As of March 23, AEMET still maintained weather alerts in parts of the archipelago, warning of lingering showers and thunderstorms even as the storm’s core weakened and shifted.

For many residents, Therese will be remembered less by its meteorological classification than by the days when the islands closed in on themselves: children logged into online classes instead of going to school; football pitches and beaches stood empty; snow fell on Teide while waves pounded the coasts.

Whether winters like 2025–26 become more frequent will depend in part on global efforts to limit warming, climate scientists say. For authorities on the Atlantic edge of the European Union, the season’s 19 named storms—and the days when Therese refused to move on—are already shaping how they plan for the next barrage of wind, rain and rough seas.