2025–26 South-West Indian Ocean cyclone season

The 2025–26 South-West Indian Ocean cyclone season is the current annual cycle of tropical cyclone and subtropical cyclone formation in the South-West Indian Ocean. It began on 15 November 2025, and will end on 30 April 2026, with the exception for Mauritius and the Seychelles, for which it will end on 15 May 2026. These dates conventionally delimit the period of each year when most tropical and subtropical cyclones form in the basin, which is west of 90°E and south of the Equator. However, tropical cyclones can form year-round with any cyclone forming between 1 July 2025 and 30 June 2026, such as 01, Awo, Blossom and Chenge, will be part of the season. Tropical and subtropical cyclones in this basin are monitored by the Regional Specialised Meteorological Centre in Réunion and unofficially by the Joint Typhoon Warning Center.

The season began with the crossover of a tropical low from the Australian basin on 16 July. The low was designated Tropical Depression 01 by Météo-France, while the JTWC designated the depression as Tropical Storm 01S a little later. The system did not strengthen and dissipated 2 days later without affecting land.

On 7 August, a tropical disturbance formed well north of the Mascarenes, later that day it was upgraded to a tropical depression then subsequently named Awo that evening as it strengthened into a Moderate Tropical Storm. Awo was the first named storm to form in August within the South-West Indian Ocean basin since Severe Tropical Storm Aline in 1969, though Severe Tropical Storm Tony did enter the basin during August in 1979. Awo only briefly survived, encountering high shear and dissipating the next day.

On 7 September, Météo–France started monitoring a disturbance south of Diego Garcia. Briefly on 9 September, it intensified into a tropical depression. The system was then classified as a Moderate Tropical Storm and named Blossom, becoming the second named storm of the season. Blossom maintained its intensity in a marginal environment, before degenerating into a remnant low–pressure area on 11 September.

On 17 October, a low–pressure area formed near Diego Garcia and was marked by Météo-France as the fourth Zone of Disturbed Weather of the season, the fourth off-season system of the season. After strengthening into a Moderate Tropical Storm, it was named Chenge. Heading westward, the cyclone further strengthened into a Severe Tropical Storm on 22 October before weakening. On 25 October, Chenge degenerated into a remnant low off the coast of Tanzania.

On 16 July, a tropical low moved into the basin from the Australian Region where it was classified as Zone of Disturbed Weather 01 by Météo-France. On the same day, the JTWC upgraded it to a Tropical Storm, assigning it the notation 01S.^[3][4] The system moved west-southwestwards into an increasingly unfavourable environment, dissipating on 18 July.

On 6 August, a tropical disturbance formed in the central Indian Ocean. A day later, the JTWC designated the system as Tropical Storm 02S, while MFR designated the system as Tropical Depression 02. Six hours later, Mauritius Meteorological Services upgraded it to moderate tropical storm status and named it Awo.^[5] Awo is the first named storm to form in August within the South-West Indian Ocean basin since Severe Tropical Storm Aline in 1969, though Severe Tropical Storm Tony did enter the basin during August in 1979.^[6]

Meteo-France Réunion began monitoring a disturbance on 7 September. At 10:00 a.m. (0600Z) on 9 September, MFR upgraded it to Tropical Depression status, marking it as Tropical Depression 03.^[7] By the next advisory it weakened back to a Tropical Disturbance. On 10 September it once again intensified into a Tropical Depression. On 11 September, it strengthened once again, this time strengthening into a Moderate Tropical Storm, thus receiving the name Blossom. It weakened shortly after and dissipated the next day.

On 17 October, a low–pressure area formed near Diego Garcia and was marked by Météo-France as the fourth Zone of Disturbed Weather of the season. It was then classified as Moderate Tropical Storm Chenge. Early on 22 October, Chenge intensified into a Severe Tropical Storm. Chenge then went on to move in a mostly western trajectory, passing north of Madagascar before entering increasingly unfavorable conditions and weakening into a Tropical Depression.

Within the South-West Indian Ocean, tropical depressions and subtropical depressions that are judged to have 10-minute sustained windspeeds of 65 km/h (40 mph) by the Regional Specialized Meteorological Centre on Réunion island, France (RSMC La Réunion) are usually assigned a name. However, it is the Sub-Regional Tropical Cyclone Advisory Centres in Mauritius and Madagascar who name the systems. The Sub-Regional Tropical Cyclone Advisory Centre (Mauritius Meteorological Services) in Mauritius names a storm if it intensifies into a moderate tropical storm between 55°E and 90°E. If instead a cyclone intensifies into a moderate tropical storm between 30°E and 55°E then the Sub-Regional Tropical Cyclone Advisory Centre (Meteo Madagascar) in Madagascar assigns the appropriate name to the storm. Storm names are taken from three pre-determined lists of names, which rotate on a triennial basis, with any names that have been used automatically removed. New names this season are: Awo, Blossom, Chenge, Dudzai, Ewetse, and Fytia, which replaced Ashley, Balita, Cheneso, Dingani, Enala, and Fabien during the 2022–23 season.^[8]

This table lists all of the tropical cyclones and subtropical cyclones that were monitored during the 2025–2026 South-West Indian Ocean cyclone season. Information on their intensity, duration, name, areas affected, primarily comes from RSMC La Réunion. Death and damage reports come from either press reports or the relevant national disaster management agency while the damage totals are given in 2025 or 2026 USD.

• Weather of 2025
• List of Southern Hemisphere cyclone seasons
• Tropical cyclones in 2025 and 2026
• Atlantic hurricane seasons: 2025, 2026
• Pacific hurricane seasons: 2025, 2026
• Pacific typhoon seasons: 2025, 2026
• North Indian Ocean cyclone seasons: 2025, 2026
• 2025–26 Australian region cyclone season
• 2025–26 South Pacific cyclone season

• Météo-France La Réunion (in French)
  • Alternative website
• Direction Générale de la Météorologie de Madagascar (in French)
• Mauritius Meteorological Services
• Joint Typhoon Warning Center (JTWC)