The winter’s first rainfall brought the temperatures down by 3 to 4 degrees Celsius yesterday, while a cold front from the north is expected to hit the city tomorrow, meteorologists said.
Shanghai reported chilly temperatures yesterday which ranged between 6 to 8 degrees with 20-to-25-millimeter precipitation in most districts.
Jinshan District had the highest precipitation of 28 millimeters, while the lowest — 13 millimeters — was recorded in Chongming Island.
An umbrella should come handy today as the rains are likely to linger across much of the city due to a north-moving warm moisture.
But the wet condition will end tomorrow when a colder air from north with heavy winds will dry the city.
Weather bureau officials said temperatures on weekdays will remain in single digits with the lowest on Friday when the mercury is expected to drop to 2 degrees. But it will be warmer on sunny Saturday when the high is likely to climb to 10.
On Wednesday and Thursday, the mercury is expected to hover between 3 to 9 degrees under cloudy skies.
The rain yesterday swept away polluting particles in the air. The density of main pollutant PM2.5 stayed below 20 micrograms per cubic meter for almost the entire day yesterday, which was less than a third of the nation’s limit 75 and 5 micrograms lower than the World Health Organization’s daily guideline value of 25. The good air quality will remain today with the AQI expected to range between 30 and 60.
But threat of hazy weather conditions remains because a stable atmosphere that usually follows a cold front could easily accumulate pollutants, said Wu Rui, a forecaster at the Shanghai Meteorological Bureau.
Local environmental authorities have released a preliminary plan in its fight against air pollution next year with a new color-coded system to mark the levels of emergency.