Skywatchers in the city will be disappointed as today's rare celestial event, "blood moon," is likely to be shaded by haze and polluted skies.
Weather forecasters said a smog has been hovering over the city since Monday as bone-chilling wind from the north brought in air pollutants. Moderate haze was recorded in the city. The air quality index reached 235 at 7am this morning, indicating heavy pollution.
A yellow alert for air pollution, the second lowest on the four-color system, was announced at 6:30am today, suggesting heavy pollution over the next 24 hours.
Moderate to heavy air pollution, along with light to moderate haze, is forecast for today, meaning the "blood moon" may not be clearly visible.
"Blood moon" is expected to last about three and half hours — from 7:48pm to 11:11pm — followed by a total lunar eclipse between 8:51pm and 10:07pm when the moon will turn coppery red, a result of sunlight on moon.
If weather conditions are fine it can be seen without telescope. The next total lunar eclipse is set to occur in 2025 or 2029, according to Tang Haiming, an official with the Shanghai Astronomical Observatory.
People are advised to pay attention to real-time forecast.
The last time "blood moon" shone over Shanghai was on October 8, 2014, when, yet again, haze enveloped the skies.
Following yesterday's blue alert, factories are required to reduce waste discharge, construction sites have to suspend outdoor work and people are urged to stay indoors.
The air quality index climbed to 274 at 10am yesterday, reaching the daily peak. The level of tiny PM2.5 particle, a major pollutant, reached 224 micrograms per cubic meter — nearly nine times the World Health Organization's standard of 25 micrograms per cubic meter for 24 hours.
The cold snap will linger for several days, accumulating pollutants. A change in wind direction is only expected on Friday, bringing in sea winds that will blow pollutants away over the weekend, the Shanghai Meteorological Bureau said.
Besides air pollution, people are also being warned to brace for freezing weather.
Morning temperature yesterday dropped to minus 2.5 degrees Celsius in downtown Xujiahui area and minus 6 degrees in Jinshan District.
It will be overcast to cloudy today, with occasional sleet in the city's southern and eastern parts.
The low temperature will hover around zero degrees in downtown areas and minus 3 degrees in suburban areas. There will be thin ice on roads.
But Thursday and Friday will be cloudy with the high rising to 6 and 7 degrees. Temperature will plummet again on Saturday, fluctuating between minus 2 degrees and 2 degrees. The low for Sunday will drop to minus 3 degrees. It may drop further to minus 4 degrees next week.