KERALA 04.06.2026; Southwest monsoon set in over Kerala on Thursday (June 4, 2026), the India Meteorological Department announced. This is three days later than the normal onset date of June 1, and four days behind the date the department had forecast.
On May 15, the IMD had predicted the monsoon would arrive over Kerala on May 26, with a model error of plus or minus four days. The actual onset on June 4 overshot even the upper bound of that window, May 30, by four days.
Having reached the coast, the monsoon is expected to gather pace. The IMD said conditions were “favourable for further advance of southwest monsoon into some more parts of central Arabian Sea, entire Goa, some parts of Maharashtra and Andhra Pradesh, some more parts of Karnataka, remaining parts of Tamil Nadu” and much of the Bay of Bengal “during next two to three days.”
Department declared the onset only after its formal criteria were met. Convective cloudiness over the southeast Arabian Sea had increased over the preceding two days; westerly winds extended up to 4.5 km above mean sea level, blowing at 20-25 knots in the lower levels; and Kerala had recorded widespread rainfall, with isolated heavy falls, over the same period. The IMD’s threshold requires that, after May 10, at least 60% of 14 designated stations across Kerala and the adjoining coast report 2.5 mm or more of rain on two consecutive days, alongside the wind-depth and cloudiness conditions — a set of tests designed to rule out a false, pre-monsoon onset.
