Abstract:The global concentration of major greenhouse gases continued to rise in 2019, and the global average〖JP〗 temperature in 2019 was 1.1 (±0.1)℃ higher than the pre industrial level, being the second warmest year on record. The ocean heat content and sea level height have reached new high levels, while the sea ice extent was at a low level. Many significant weather and climate events occurred in 2019, including torrential rains and floods in many places, droughts in Australia and many countries in Asia and Europe, frequent extreme tropical cyclones, unusually high temperature and heat waves in Europe and Australia, cold and heavy snowstorms in North America and Europe, as well as severe convective weather in many regions. The positive phase of the Indian Ocean dipole (IOD), the continuous warming of the sea surface temperature in the equatorial central Pacific and the control of the subtropical high pressure system were the main causes of high temperature and little rain in Australia, resulting in serious forest fires. The continuous heavy rainfall in India from July to August was mainly due to the abnormally strong positive phase of IOD and the tropical depression with unusually long duration.