One hundred and nineteen years (1872--1990) of area-averaged rainfall over India, and sea surface temperature (SST) averaged over the equatorial central and eastern Pacific Ocean (the so-called Ni¿o3 region) as an index of El Ni¿o-Southern Oscillation (ENSO) are analyzed to study their covariability. The monsoon rainfall, SST, and their covariability undergo decadal-multidecadal variations without any dominant or distinct periodicities. The monsoon rainfall, SST, and their covariability are compared to solar irradiance at the top of the Earth's atmosphere for the same data period. At the 11 years time scale there is no consistent relationship between the monsoon rainfall and solar irradiance, and between the Ni¿o3 SST and solar irradiance. The rainfall and irradiance appear to covary with nearly the same phase at multidecadal time scales. The Ni¿o3 SST and irradiance appear to covary with nearly opposite phases at multidecadal time scales. The interannual covariability of the monsoon-ENSO system is also apparently modulated by this multidecadal variability. Based on these results, a hypothesis about the possible influence of solar irradiance in the ENSO-monsoon relationship at multidecadal time scales is described.¿ 1997 American Geophysical Union