明天起，北京或将入冬

Core Viewpoint - A strong cold air mass is expected to significantly lower temperatures across China, with Beijing likely to experience its earliest winter onset in years, potentially starting on October 18, 2023 [4][8]. Summary by Sections Weather Impact - The cold air mass will affect most regions of China, bringing the lowest temperatures since the second half of 2023, with Beijing's temperatures expected to drop to single digits starting from October 17 [2][6]. - Continuous average temperatures below 10°C are forecasted for Beijing from October 18 to 24, indicating a high probability of winter onset [4][8]. Temperature Predictions - The average temperature in northern regions, including Beijing, is expected to remain below 10°C for at least five consecutive days starting October 18, which meets the criteria for winter [6][8]. - Initial frost conditions are anticipated in northern areas, including parts of Liaoning, during this period [6][8]. Weather Warnings - The Beijing Meteorological Station has issued blue alerts for cold waves and strong winds, predicting a temperature drop of around 8°C from October 16 to 18 [8]. - Specific regions in Beijing are under frost warnings, indicating potential agricultural impacts due to low temperatures [8]. Health Advisory - The Beijing Center for Disease Control advises residents to take precautions against the cold, including wearing appropriate clothing and maintaining hygiene to prevent respiratory illnesses during the flu season [9].