"Open the window for a while and the ground is full of water. I feel like I can 'skate' on the floor at home." On the first working day of the year of the tiger, Haikou, Hainan encountered "going back to the South", joked Ms. Wang, a citizen. On the 7th, the northern part of Hainan Island "woke up" from the continuous overcast and cold weather during the Spring Festival holiday, ushered in a sunny day, and the maximum temperature rose from less than 20 ℃ to about 25 ℃. However, the rapid alternation of cold and warm has brought the "back to the South" of "sweating" on the floor and wall this year. From January to March every year, Qiongbei area where Haikou is located is most prone to repeated "back to the South". Zheng Yan, chief forecaster of Hainan Meteorological Observatory, said that after the cold air left, the warm and humid air flow quickly counterattacked, resulting in the rise of temperature and the increase of air humidity. After some cold object surfaces encounter the warm and humid air flow, they condense and produce water droplets. This is "back to the South". Zheng Yan said that affected by the cold air tomorrow, the maximum temperature in the north and Middle East of Hainan Island will drop significantly, and the "back to the South" will disappear. "I mopped the floor today. I turned on three fans and it was still wet all day." Netizen "Mo - an Hao" said. "Cool down and rain, restart the wet and cold mode, and pay attention to dressing and keeping warm at work tomorrow." The official microblog of Haikou meteorological observatory reminded the public when it released the weather forecast on the afternoon of the 7th. According to the Hainan Provincial Meteorological Observatory, from August 8 to 9, affected by the cold air, there was light rain on cloudy days in the northern, Eastern, central and western regions of Hainan Island, and cloudy days in the southern region, which had a certain impact on transportation. At present, it is the peak of the return trip after the festival. From 8:00 on the 7th to the 10th, there is light rain on a cloudy day in Qiongzhou Strait, and the navigation meteorological conditions are general; The weather conditions were good from October 10 to 12. Qiongnan, where Sanya is located, has no trouble of "returning to the South". As a well-known tourist destination in China, Sanya holiday tourism market is as hot as the weather. Sanya Phoenix International Airport is expected to be the peak of outbound passenger flow from July 7 to 15. Passengers are reminded to travel off peak and actively cooperate with the inspection related to epidemic prevention and control. (outlook new era)