强冷空气来袭，上海下周二和周三将出现小雨夹雪或小雪天气

Group 1 - The core point of the article discusses the weather conditions in Shanghai, highlighting the occurrence of fog with visibility less than 500 meters due to radiation cooling and moist air from the southeast wind [1][3] - On January 16, the fog gradually dissipated by noon, with daytime temperatures reaching around 19 to 20 degrees Celsius, specifically noting a high of 19.7 degrees Celsius at the Xujiahui station [1] - The weather forecast indicates a significant temperature drop next week due to strong cold air, with expected temperatures between 3 to 5 degrees Celsius and potential light rain or snow on January 17 and 18 [3]