Two-year sea-surface temperature time series of satellite data at two sites in the equatorial Indian Ocean are examined for oscillations with periods 2--70 days. The wavelet transform of the signals reveals a changing wavelet spectrum between August 1987 and November 1987 in the 10--30 day range, while the same time period in 1988 shows a relatively fixed spectrum. At 3¿ latitude and 53¿ E the 1987 wavelet coefficients with scales 10--30 days have about twice the amplitude they have in 1988. At 3¿ latitude and 56¿ E the 1987 waves have roughly half the amplitude as the 1988 waves. Activity with wavelet spectral peaks at periods near 12 days often precede these waves.