A met official said while there was an increase in fog, pollution levels have not necessarily increased.
An unusually dense cover of smog has enveloped larges large parts of Mumbai on Thursday morning, the met department said. The sudden spike in fog was a result of cold and warm winds meeting, officials explained.
"Minimum temperatures have been lower than normal in Mumbai. Westerly winds from the Arabian Sea which are warmer and bring in moisture have mixed with colder winds, which have created the fog," said Ajay Kumar, a senior official at the meteorological department in Mumbai.
Mr Kumar, however, said while there was an increase in fog, pollution levels have not necessarily increased. "This is more of a meteorological phenomenon. And with exisiting pollution levels, the end result is smog," he said.
The Bombay High Court, meanwhile, is hearing a petition on whether the odd and even scheme to control movement of vehicles should be implemented in Mumbai like in Delhi.
The Maharashtra government, however, did not file its reply today and the court has asked the state, the Centre and the Brihanmumbai Municipal Corporation to submit their replies by February 9.
Earlier, Chief Minister Devendra Fadnavis had told NDTV that though it was a "good scheme", it was not required in Mumbai where most people unlike Delhi travelled by public transport.