Coral spawning times have been linked to multiple environmental factors; however, to what extent these factors act as generalised cues across multiple species and large spatial scales is unknown. A unique data set of coral spawning from 34 reefs in the Indian and Pacific Oceans was used to test if the month of spawning and peak month of spawning in assemblages of Acropora spp. can be predicted by sea surface temperature (SST), photosynthetically active radiation, wind speed, current speed, rainfall or sunset time. SST derivatives were the best predictor of both month (R2 = 0.73) and peak month (R2 = 0.62) of spawning These findings suggest that rapidly increasing SST are the most effective cue to synchronise spawning over large geographical scales, most probably to ensure high fertilisation success. Therefore, climate change could lead to a decoupling of proximate cues from selective pressure, with detrimental effects on coral population replenishment.