1969–70 South-West Indian Ocean cyclone season

Severe tropical storm (MFR)
Duration	August 19 – August 22
Peak intensity	100 km/h (65 mph) (10-min);

Aline existed from August 19 to August 22.

Tropical cyclone (MFR)
Duration	October 7 – October 15
Peak intensity	130 km/h (80 mph) (10-min);

October 7 to October 15.

Moderate tropical storm (MFR)
Duration	November 11 – November 21
Peak intensity	85 km/h (50 mph) (10-min);

26 deaths in Comoros and Mozambique.[1]

Moderate tropical storm (MFR)
Duration	December 29 – January 1
Peak intensity	65 km/h (40 mph) (10-min);

Delphine existed from December 29 to January 1.

Tropical cyclone (MFR)
Duration	January 10 (entered basin) – January 16
Peak intensity	130 km/h (80 mph) (10-min);

This system entered the basin on January 7 and dissipated on January 17.

Moderate tropical storm (MFR)
Duration	January 7 – January 11
Peak intensity	65 km/h (40 mph) (10-min);

The storm struck western Madagascar, bringing rainfall.[2]

Tropical cyclone (MFR)
Duration	January 10 – January 19
Peak intensity	120 km/h (75 mph) (10-min);

Four deaths in Madagascar due to flooding.[3]

Tropical cyclone (MFR)
Duration	January 22 – January 27
Peak intensity	120 km/h (75 mph) (10-min);

One death on Reunion.[4]

Very intense tropical cyclone (MFR)
Duration	February 3 (entered basin) – February 13
Peak intensity	220 km/h (140 mph) (10-min);

Iseult existed from February 2 to February 15.

Very intense tropical cyclone (MFR)
Duration	February 11 (entered basin) – February 28
Peak intensity	230 km/h (145 mph) (10-min);

It was named Josephine in its formative stages due to being in what was considered the Australian basin at the time.[5]

Moderate tropical storm (MFR)
Duration	March 16 – March 26
Peak intensity	85 km/h (50 mph) (10-min);

Katia existed from March 16 to March 26.

Tropical cyclone (MFR)
Duration	March 20 – April 1
Peak intensity	155 km/h (100 mph) (10-min);

Louise existed from March 20 to April 1.

Tropical cyclone (MFR)
Duration	March 26 (entered basin) – March 30
Peak intensity	140 km/h (85 mph) (10-min);

Michelle entered the basin on March 24 and dissipated on March 30.