We report the first test of the Synthetic Storm Technique (SST) at the equator, in the Isle of Guam, where NASA has installed an interferometer at its Remote Ground Terminal Complex, composed of two terminals separated by 600 m in the North–South direction. The total tropospheric attenuation refers to experimental measurements at 20.7 GHz, obtained in a 38° elevation–angle slant path to a geostationary satellite. Two conventional tipping–bucket rain gauges have also continuously recorded rain–rate time series, necessary for the SST simulations. The results show that both single link and site diversity link probability distributions are very well predicted by the SST. The normalized diversity gain sets at about 15~20 % of the single site attenuation less than about 15~20 dBs.