World Weather/Climate Extremes Website

World: Greatest Twenty-four-Hour (1 Day) Rainfall

Record Value 1.825m (71.8")
Date of Record 7-8/1/1966
Length of Record 1966-1990
Instrumentation Tipping-Bucket Rain Gauge
Geospatial Location Foc-Foc, La Reunion [21°14'S, 55°41'E, elevation: 2990m (9810ft)]

References

Holland, G.J. (1993): WMO/TC-No. 560, Report No. TCP-31, World Meteorological Organization; Geneva, Switzerland. Also by Philippe Caroff (Operation Head RSMC/TC Warning Center, La Reunion)

Discussion

Event occurred with passage of Tropical Cyclone Denise in South Indian Ocean. Reunion Island is located approximately 670 kilometers east of Madagascar in the Indian Ocean. Extreme orography (mountains to 3300 meters and steep valleys) amplify orographic uplift.

A old and mistaken value of a 24 hr. rainfall of 1.870 m (73.62’’) at Cilaos, La Reunion, on 15-16 March 1952 (cited by J.L.H. Paulhus [Indian Ocean and Taiwan Rainfalls Set New Records, Monthly Weather Review, 93 (5), 1965, pp. 331-335], is sometimes quoted. However, Reunion meteorologists state that Cilaos value is "an old mistake." They do confirm that this figure is invalid and that the accurate 24h rainfall extreme is 1.825 mm recorded at Foc-Foc during tropical cyclone Denise in 1966.

Foc-Foc, La Reuinion

Closeup Satellite Image of Foc-Foc, La Reunion, South Indian Ocean

Foc-Foc, La Reunion

Regional Satellite Image of Foc-Foc, La Reunion, South Indian Ocean