Core Viewpoint - The article discusses the weather conditions in Shanghai, highlighting an unusually warm start to spring with temperatures reaching 17°C, potentially the warmest in nearly 20 years for the beginning of spring, but warns of an imminent drop in temperature and rain [1] Weather Conditions - Shanghai is experiencing a maximum temperature of 17°C today, which may set a record for the warmest "Lichun" (Beginning of Spring) day in nearly 20 years [1] - The average temperature in Shanghai typically does not indicate the arrival of spring until around the "Jingzhe" (Awakening of Insects) solar term in mid-March [1] - The city is currently in winter, with cold air still prevalent, and "Lichun" is noted as a period with frequent frost warnings [1] Historical Context - The highest temperature recorded on "Lichun" was 20.8°C in 2004, while a cold wave brought temperatures down to -1.0°C in 2018 [1] - The warmest "Lichun" day in the last 20 years was on February 4, 2007, with a maximum temperature of 16.1°C [1] Upcoming Weather Changes - Following the warm weather, a shift to cloudy and rainy conditions is expected tomorrow, with significant rainfall anticipated at night [1] - A strong cold front will lead to a drop in temperature, with forecasts predicting daytime temperatures below 6°C on Friday, resulting in a damp and cold feeling [1] - The weekend is expected to bring clear but cold weather, with morning and evening temperatures potentially dropping below freezing, possibly setting new lows for the winter season [1]