Mumbai: The city is set for four days of heavy rain from Wednesday, with the India Meteorological Department (IMD) issuing an orange alert for the city till July 4, warning of heavy to very heavy rainfall, thunderstorms, lightning and gusty winds at isolated places.Thane, India - June -30, 2026: Heavy rainfall has been lashing Thane city since early this morning ,in Thane ,in Mumbai, India, on, Tuesday, June -30, 2026. ( photo by Praful Gangurde / Hindustan Times ) (praful Gangurde)According to IMD officials, strong westerly winds, an upper-air cyclonic circulation near Gujarat and an active shear zone are expected to strengthen the monsoon over the Konkan coast, leading to widespread heavy rainfall over the next four days.The IMD upgraded the alert to orange from yellow on Tuesday evening after moderate to heavy showers lashed the city throughout the day, causing waterlogging, traffic congestion and delays in suburban train services.Water accumulated in low-lying areas, including Kurla, while the Andheri subway was closed to traffic. Local trains on the Central, Western and Harbour lines ran 15 to 20 minutes behind schedule, and traffic slowed in Malad, Goregaon and Mulund.However, rainfall remained uneven across the city on Tuesday. The Santacruz observatory recorded 27.8 mm of rain in the 24 hours ending 8am Tuesday, while the Colaba observatory received 31.8 mm.Between 8am and 11pm, the western suburbs received an average of 88 mm of rain, followed by 79 mm in the eastern suburbs and 68 mm in the island city.