Maldives is a nation that only has two seasons: The Northeast (Iruvai) Monsoon from December to April which is the dry season, and the Southwest (Hulhangu) Monsoon from May to November which is the wet season. And during the Southwest Monsoon, Maldives experiences an increased amount of swell waves, a phenomenon that is cause for caution and inflicts damage close to and directly where they hit.
Swell Waves: What They Are and Their Impacts
Swell waves (or sea swells, tidal swells) are caused by strong winds or distant storms and can travel thousands of kilometers even during calm weather. To put it more accurately, according to the Bureau of Meteorology in Australia and the National Disaster Management Authority (NDMA) of Maldives, deep-low pressure systems and tropical cyclones in the southern parts of the Indian Ocean or the Arabian Sea sending long wave trains are the cause of swell waves.
There are other causes of swell waves as well, such as wind patterns that persist for long periods of time, monsoonal winds and tidal influence.
Swell waves carry with it a number of risks, which can be particularly dangerous for Maldives. One of the main risks is coastal flooding and erosion. Erosion is something that affects over 90 percent of the islands in Maldives, with the resulting land loss being a major cause of worry.
Another risk is damage to the infrastructure. Swell waves carry with it a lot of energy and when they crash, they tend to cause quite a bit of damage to coastal roads in Male’ and harbors as well.
Transport disruptions are another risk that should be observed. In the past, the Maldives Meteorological (MET) Office has issued alerts of swell waves appealing to the public to exercise caution when driving along the Sinamale’ Bridge, especially if an individual is driving a two-wheeled vehicle. Traveling by sea can also be dangerous when swell waves are active, with the MET Office urging caution previously.
Types of Swell Wave Alerts to be Aware Of
There are four types of alerts to be aware of when swell waves occur, as per the NDMA.
White Alert: Information
White Alerts carry the lowest risk, with minor notable activity expecting to have a limited impact.
Yellow Alert: Advisory
Yellow Alerts have the capacity to cause flooding, while minor, and have the potential to affect five islands at the very least.
Orange Alert: Warning
These alerts can affect up to ten islands at least and can cause moderate to significant impacts.
Red Alert: Severe Warning
The most dangerous alert, capable of causing extensive damage and coastal flooding.
The MET Office issues timely alerts on their social media pages, particularly on X, and is the best way to stay informed during swell wave periods.
Past and Recent Swell Wave Incidents in Maldives
2024
- On 21st July 2024, the MET Office issued a White Alert predicted swell waves would occur from Kaafu Atoll to Addu between 1:00 pm to 5:15 pm at high tide, with waves projected to reach 2.8 feet during the high tide in Central Maldives and 3.2 feet in Southern Atolls. The Male’ Raalhugandu area in Henveiru and the southern side experienced swell waves the week before as well.
2025
- On 26th June 2025, Male’ experienced strong swell waves near the Carnival area, the eastern side and the southern side where the Industrial Zone is.
- The MET Office stated on 27th June 2025 that northern atolls would be susceptible to high tides at around 2:29 pm, with Central atolls seeing high tides around 3:12 pm with waves reaching 2.7 feet.
- On 28th June 2025, the MET Office issued a White Alert across Maldives from 1:30 pm to 5:00 pm citing swell wave surges. This time around, the MET Office asked the public to use four-wheeled vehicles for transport if they were to cross the Sinamale’ Bridge and the highway during said hours.
- On 19th July 2025, the MET Office issued a White Alert from 9:45 am to 3:30 pm, citing bad weather conditions across Maldives, with swell surges and rough seas to be expected as well.
2026
- 26th July 2026 saw flooding and damage across various areas in Male’, with the Industrial Village and the Raalhugandu area being affected the most, and the Carnival area seeing seawater damage to parked cars and motorcycles. The waves had reached and entered cafes along the beachfront as well. Motorcycles parked in the Raalhugandu area were swept into seawater by the waves.
- The MET Office issued a White Alert on 27th July 2026, forecasting swell waves from 10:30 am to 3:00 pm. They also issued a forecast stating a risk of further sea swells over the next two days, which can be attributed to the full moon on 28th July and its closer-than-usual orbit to the Earth, which expected to produce higher-than-normal tides.
- The MET Office issued another White Alert on 28th July 2026, with swell waves being forecasted across the country. The alert was issued from 11:30 am to 3:30 pm. They also stated that the risk of swell waves would extend until 29th July.
- The MET Office also issued tidal forecasts for 26th July with waves up to 0.95 meters at 12:02 pm, 27th July with waves up to 0.81 meters at 12:53 pm and 29th July on the day of the Full Moon with waves up to 0.98 meters at 1:40 pm.
The Global Climate and How Swell Waves Have Affected Maldives
It is no secret that the climate across the world has been getting hotter with each passing year, with Maldives being one of the countries that are in the danger zone for rising sea levels. This means that over the coming years, swell waves will have a more adverse effect on Maldives’ shorelines.
Coastal erosion has a potential of acceleration in Maldives and is a cause of worry to the island nation. The loss of land along the coast has been documented heavily in Maldives and combined with powerful swell waves that batter islands, the waves are seen as an environmental hazard.
Rising sea levels do not help either, as the height of the swell waves will increase with the increase in sea level rise as time goes on. This will also increase the impact flooding would have as a secondary result of swell waves. There are already reports that swell waves have reached inland on islands, flooding people’s homes and businesses, along with the streets, sometimes making it dangerous to walk or drive. There have been major flooding incidents caused by swell waves that have occurred in 1987 and 2007, as per a research paper that was deposited to HAL (Hyper Articles en Ligne).
Swell waves have also reportedly damaged mangroves, a type of vegetation responsible for stabilizing shorelines. This has a direct impact on the strength of coasts and the surrounding biodiversity, negatively affecting the environment as a whole.
Research and investigations from AGU.org dating between 1985 to 2018 has shown that the power of swell waves from the Southern Ocean that radiate across the Indian Ocean may be the reason why there is an increase in wave power, with the extratropics influencing wave power as well. The higher the power swell waves have, the higher the risk of damage that cascades across Maldivian coastlines.
Climate change will continue to have negative consequences on the globe, and Maldives is feeling the brunt of it as well. While rising sea levels may be the main villain for the island nation, swell waves are also and have been known to inflict lasting damage environmentally and infrastructurally.
