Cyclones, Heatwaves and Flooding Forecast for Mauritius Summer 2025-2026

Mauritius: Islanders are bracing for a potentially volatile summer as the latest seasonal forecast, delivered by the Vacoas Meteorological Station on Monday, November 3, indicated an increased risk of tropical storms, intense heatwaves, and localised flooding for the 2025-2026 season.

The most severe warning comes in the form of elevated cyclone activity, with forecasters anticipating more than ten moderate tropical storms forming, primarily to the east of Diego Garcia. Winds within these systems are projected to reach speeds of 90 to 100 km/h around the centre.

Cyclone and Storm Surge Warning

While not all storms will directly impact the island, officials caution that one or two systems could pass close by, bringing with them waves of 10 to 12 metres, coupled with significant swell and storm surges.

An increasing trend in the number of storms reaching cyclone status has been observed between 1975 and 2024. Forecasters warn of the possibility of rapid intensification in these severe weather events.

Heatwave and Uncomfortable Conditions

On the temperature front, the summer is expected to bring figures slightly above average. On some days, temperatures could exceed seasonal norms by 2°C to 3°C, potentially peaking at 36°C, particularly along the western coast.

Periods of high humidity combined with light winds are expected to create torrid and uncomfortable conditions for residents.

Intense Rain and Flood Risk

While the overall rainfall is projected to be slightly below the usual average (expected at 1,150 mm, or approximately 85% of the average), the nature of the precipitation presents a risk.

• The start of the rainy season could be delayed until the second half of December.
• A cumulative rainfall of 50 mm is expected over five days.
• Crucially, there is a risk of short-duration, heavy rain episodes which are likely to cause localised flooding.
• The annual number of days with precipitation exceeding 50 or 100 mm is already showing a progressive increase over the years.

Other Extreme Weather Possible

Beyond the primary risks, the head of the meteorological service, Prithviraj Booneeandy, indicated that the 2025-2026 summer may see other extreme phenomena, including:

• Heatwaves above the average.
• Rain accompanied by thunderstorms.
• The possible formation of mini-tornadoes.

New Framework for Enhanced Forecasts

The meteorological service is adopting the ‘National Framework for Climate Services’ to better structure and organise its climate information, aiming to optimise forecasts.

This new framework will provide comprehensive data on rain, temperature, wind, sunshine, and humidity, offering three-month forecasts and information on dry and wet periods.

This enhanced system is already providing key indicators for the agricultural sector, such as relative humidity and hours of sunshine, essential for crop planning and water management.

Source: l’Express