seasonal forecast for February, March, April

Updated 10 April 2017

For the April-May-June season, the prevailing inter-monsoon conditions are expected to prevail and extend into May 2017. During this period, prevailing winds are light and variable in direction, and the weather patterns are typically characterised by afternoon showers. The monsoon rain band is expected to migrate towards the north, and a gradual increase of shower activities can be expected over the northern ASEAN region. The increased shower activities would help alleviate the hotspot and haze situation in the northern ASEAN region. In the southern ASEAN region, frequent shower activities are expected to continue to persist. However, occasional isolated hotspot activities can still be expected during brief periods of dry weather conditions.

In the second week of April, a strengthening of north-easterly winds can be expected and this would bring drier than usual conditions over the Mekong sub-region. During the same period, near to above-normal rainfall is expected for most parts of the southern ASEAN region. In the third week of April, drier than usual conditions are forecast for the Philippines while near-normal rainfall is expected for the rest of the region.

By June 2017, the inter-monsoon conditions are expected to give way to the onset of the Southwest Monsoon conditions, and mark the beginning of the traditional dry (wet) season of the southern (northern) ASEAN region. For the southern ASEAN region, extended periods of dry weather conditions can be expected and this could lead to an increase or escalation in hotspot activities over the fire-prone provinces of Sumatra and Kalimantan. Typically, in the early part of the traditional dry season in the southern ASEAN region, most of the fires emerge in northern and central Sumatra and western Kalimantan.

For the April-May-June 2017 season, near-normal rainfall is expected over most parts of the Mekong and southern ASEAN region. In April 2017, slightly above-normal rainfall is forecast for Thailand. In June 2017, slightly below-normal rainfall is expected for South Sumatra and West Kalimantan.



  • 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)