Why was it so cold last year?

Cold wave plus cooling. According to the statistics of the National Climate Center, compared with the same period in history, the frequency of cold air activity has not been much since this winter. During the period of 65438+ in February, 2020, there were two cold air processes affecting China, namely, the period from 65438+ in February, 2020 to 65438+ in March (national strong cold air), and the period from 65438+ in February, 29, 2020 to 65438+ in October, 2026. These two times are national cold air processes, with large influence range and strong cold air intensity.