TODAY is set to be the coldest day since winter was officially declared on December 1, with temperatures below freezing due to the influence of a strong cold front from the north, forecasters said yesterday.
However, the mercury will climb gradually from tomorrow, the Shanghai Meteorological Bureau added.
The bureau issued a blue alert for gales, the lowest level in a four-tier warning system, on Monday night, and had not lifted this alert by last night.
The lowest temperature was 3.2 degrees Celsius in downtown areas yesterday and 1.3 degrees for Chongming — the lowest among suburban areas. The high scraped 5.7 degrees in downtown.
Heavy air pollution shrouded the city on Monday night, with the arrival of pollutants from the north by carried by the cold front.
This brought a high level of PM2.5, tiny particles that are especially harmful as they can penetrate deep into the respiratory system.
The situation started to improve yesterday morning with the air quality index 101 at 8am — slightly polluted — and 93 at 5pm, fine, according to the index.
Air quality is forecast to be fine today, with larger PM10 particles the main pollutant, according to the Shanghai Environmental Monitoring Center.
Fine weather is forecast this week. Today should see sunshine with some cloud, with temperatures down to minus-1 in downtown areas and a high of 6 degrees, according to the bureau.
In suburban areas, it will be colder, with the lowest temperatures 2 to 4 degrees below zero. Strong winds are also forecast.
Temperatures will rise
From tomorrow, temperatures will rise. It should again be sunny with some cloud, with the mercury ranging between 1 and 9 degrees.
On Friday, the temperature will climb to between 4 and 11 degrees, and it should be cloudy.
It is also forecast to be cloudy on Saturday, with the mercury between 5 and 10 degrees.
On Sunday, the temperature will drop to a low of 2 and a high of 7 degrees. It should be sunny to cloudy.
Winter officially begins in Shanghai when the city experiences five consecutive days where the temperature remains below 10 degrees. The first day of the sequence is the start of winter.