Many studies linked the climate change impact on coral bleaching without a good basic understanding of climate science, particularly with regard to the utilization of climate change term. If the climate is changing yearly and temperature is continuously rising, then coral reef may suffer from bleaching annually. The statement should be corrected because climate change may lead climate variabilities will be likely to occur very often in frequency which further become a serious threat on coral biodiversity as well as its ecosystem that might lead to mass mortalities. The purpose of the study is to prove that two natural climate variabilities, ie, El Niño and Southern Oscillation (ENSO) and Indian Ocean Dipole are responsible for coral bleaching in certain period and occassionally in Weh Island as well as to straighten the meaning of climate change term as often used in many coral bleaching studies. The result show that the increase of Sea Surface Temperatures (SST) leading to bleaching watch status are preceded by emergences of ENSO and dipole mode from Indian Ocean. It is also shown that SST has slowly increased that may lead these climate variabilities to occur very often in future climate. In conclusion, the increase of ENSO and dipole mode frequencies become a serious threat to coral biodiversity which may bring a new status of home of lost corals in Weh Island.