贵阳已开启降温，今晚东北部局地有冻雨

Group 1 - The core viewpoint of the articles highlights the impact of a strong cold air mass on Guiyang, leading to significant temperature drops and the potential for freezing rain in certain areas [1][3][4] - The temperature in the northeastern part of Kaiyang County has already dropped to between 6 to 8 degrees Celsius, with a notable decrease from a high of 16.5 degrees Celsius to 8.3 degrees Celsius within four hours [1] - The weather forecast indicates that from the night of January 19 to the day of January 20, there will be overcast skies with light rain and freezing rain in higher terrain, with temperatures in the main urban area expected to range from 2 to 13 degrees Celsius [3] Group 2 - The forecast for January 20 to January 21 predicts continued overcast skies with freezing rain and road icing, with temperatures in the main urban area expected to be between -1 to 2 degrees Celsius [4] - From January 21 to January 22, the freezing rain is expected to transition to overcast skies, with temperatures dropping further to between -2 to 3 degrees Celsius in the main urban area [4] - The weather is expected to improve slightly from January 22 to January 23, with daytime temperatures rising to between -2 to 9 degrees Celsius, although frost is still anticipated in higher terrain at night [4]