seasonal forecast for March, April and May

Updated 12 March 2018

During the period from March to May 2018, the region will gradually transition from the current Northeast Monsoon season to the inter-monsoon period towards the end of March 2018. The inter-monsoon period (April and May) is a transition period where the low level winds in the region are generally light and variable in direction and an increase in shower activities can be expected in the ASEAN region.

The traditional dry season of the northern ASEAN region will continue to prevail for the rest of March 2018. There would still be occurrences of hotspot activities with smoke plumes and haze in the Mekong Sub-region but a gradual decrease in the number of hotspot activities can be expected with the expected increase in shower activities as the inter-monsoon period sets in. In April and May 2018, there could still be occurrence of isolated hotspot activities in parts of the northern ASEAN region during brief periods of drier weather.

During the outlook period (March – May 2018) for the southern ASEAN region, there could be brief periods of drier weather but overall, wet weather conditions are expected for most parts of the region. The increase in shower activities in the coming months would help to subdue hotspot activities in the region.

For the March-April-May 2018 season, slightly below-normal to near-normal rainfall is forecast for most parts of Southeast Asia except for the Philippines where slightly above-normal rainfall is expected. In March and April 2018, slightly above-normal rainfall is forecast over the northern parts of Kalimantan and Sulawesi, and western part of Papua.



  • Legend
  • Above Normal
    (67th to 100th percentile)
  • Slightly Above Normal
    (50th to 83rd percentile)
  • Normal
    (33rd to 67th percentile)
  • Slightly Below Normal
    (17th to 50rd percentile)
  • Below Normal
    (0 to 33rd percentile)