Most parts of coastal Kerala receive more than 50 HR events/season except the southernmost parts which receive 40–50 HR events/season during the southwest monsoon season. In line with the decreasing trend in the Kerala averaged seasonal rainfall during the southwest monsoon season, significant negative trends were observed in the frequency of MR (≥5 mm to 100mm) as well as HR (> 100mm) events (at 99.9% and 95% respectively) over the state during the period (1901-2021). Spatially, frequency of both MR and HR events exhibit decreasing trends over most parts of Kerala. However, in the last 50 years, significant increase in the HR events have been observed over some areas of eastern part of the state where exceptionally heavy rainfall spells of shorter durations and landslides were experienced in the recent years. In decade (10 days period) wise trend analysis for MR events during July and August, third decade of July (21–31 July) showed significant negative trend for the entire period (99%), second decade of August (11–20 August) showed significant negative trend (95%) for the second part of the data period. In case of HR events, first and third decades of July (1–10 July; 21–31 July) showed significant negative trends (95% and 99.9% respectively)