The 1997–98 South-West Indian Ocean cyclone season was fairly quiet and had the latest start in 30 years.

The first tropical disturbance originated on January 16, although the first named storm, Anacelle, was not upgraded until February 8, a record late start.

Many of the storms suffered from the effects of wind shear, which contributed to there being only one tropical cyclone – equivalent to a minimal hurricane.

Although Anacelle was the first named storm of the season, another tropical depression preceded it that crossed Madagascar several times.

[4] For the early portion of the season, there were unusually quiet conditions across much of the basin, along with higher than normal pressure.

The Intertropical Convergence Zone (ITCZ) associated with the monsoon only became active in February, allowing tropical cyclogenesis to occur more frequently.

Moving southwestward, the system organized into a tropical depression on January 17, developing a curved band of convection.

[1] On January 18, the JTWC classified the system as Tropical Cyclone 13S, estimating winds of 65 km/h (40 mph),[3] despite the storm being 55 km (35 mi) inland.

[5] The agency quickly downgraded the storm to tropical depression status, but briefly re-upgraded it on January 19 as the system crossed over the extreme western Mozambique Channel.

[6] The depression approached tropical storm intensify after developing increased convection over the center, but it weakened again on January 22.

[1] In its formative stages, the depression dropped beneficial rainfall in the Comoros, reaching 163 mm (6.4 in) at Prince Said Ibrahim International Airport.

[1] The rains caused landslides and flooding in the country, which disrupted transport in three provinces, damaging several bridges.

[7][8] The most significant landslide occurred in Milange District at nighttime, which swept houses into a river; about 2,500 people were left homeless in the village.

Conditions were favorable for further strengthening, although the system made landfall in western Madagascar between Maintirano and Morondava on February 5.

Late on February 8, the system reached the open waters south of Madagascar and quickly redeveloped convection southeast of the center, displaced by wind shear, and it was reclassified as a subtropical depression.

[3] A building ridge to the south turned the system northeastward on February 10 and later to the northwest, bringing it back over southwestern Madagascar.

On February 11, the circulation again reentered the Mozambique Channel, and subsequently the thunderstorms rebuilt over the poorly defined center.

An increase in convection on February 15 organized into a curved band, and MFR upgraded the system to Tropical Storm Beltane on the next day off the west coast of Madagascar.

[1] The JTWC also classified the system as Tropical Cyclone 23S on February 16,[3] possibly due to the extended duration between issuing advisories.

[11] Strong wind shear stripped the convection from the center as Beltane approached southwestern Madagascar on February 17.

Another building ridge turned the weakened depression to the northwest across the Mozambique Channel, finally dissipating on February 20 near the mouth of the Zambezi.

Anacelle developed an eye feature on February 10, indicating that it attained tropical cyclone status, or winds of at least 120 km/h (75 mph).

[15] A large area of low pressure between the Chagos Archipelago and the Mascarene Islands spawned a small tropical disturbance on March 4.

[3] Increased convection organized into a central dense overcast, and Donaline intensified into a minimal tropical storm,[1] reaching peak winds of 75 km/h (45 mph) according to the MFR.

[3] By that time, the storm was moving steadily to the southwest due to a trough in the region related to the remnants of Donaline.

On March 20, the circulation became exposed from the thunderstorms and approached 80 km (45 mi) east of Mauritius,[1] producing wind gusts of 70 km/h (45 mph).

The disturbance continued to organize and developed a central dense overcast over the center, becoming Tropical Storm Gemma on April 8.

[20] After Cyclone Anacelle became extratropical, an area of convection developed about 700 km (430 mi) northeast of Rodrigues on February 14.

[1] Named Tropical Cyclone 34S by the JTWC, it moved westward throughout its duration but failed to intensify due to wind shear.

The last disturbance of the year formed on July 20 about 1480 km (920 mi) east of Diego Garcia.