Monsoon periods
The broad seasonal calendar is northeast monsoon in December–February, first inter-monsoon in March–April, southwest monsoon in May–September and second inter-monsoon in October–November. Individual days can differ substantially from the usual pattern.
A forecast for the right place
Check the destination you will actually visit, including its elevation. A city forecast does not describe a mountain trail, offshore boat trip or every beach on the same coast. Ask providers about the conditions at their activity site.
Rain and travel plans
Build flexibility into long road transfers and outdoor days. If there are warnings, use local authority and operator advice to change the route. Do not plan a waterfall swim, exposed hike or sea excursion solely around a monthly average.
Pack for more than one setting
Carry practical rain protection and protect documents and electronics. If the itinerary includes hills as well as coast, add a layer and footwear appropriate to the planned walks. Keep essential items accessible on transfer days.