BMKG Weather Forecast for 21 May 2026: Beware Heavy Rain in Three Regions

BMKG issued early warnings of potential significant weather expected to affect a number of regions in Indonesia on Thursday, 21 May 2026. The current atmospheric conditions are triggered by the appearance of two cyclonic circulation centers monitored in Indonesian waters. The public is urged to remain vigilant, especially in areas categorized as Alert for potential heavy-to-very heavy rainfall.

Based on the latest atmospheric dynamics, two cyclonic circulations were observed forming in the Western Indian Ocean, off Lampung, and in the Northern Pacific Ocean near Papua. This system triggers the formation of convergence and confluence zones in the Western Indian Ocean near Lampung, the northern waters of Papua, and around the center of those circulations. In addition, other convergence zones have formed along the northern coast of Aceh, the Malacca Strait, and extending from West Sumatra to the western Bengkulu waters. Similar phenomena are observed across central and eastern Indonesia, from Central Kalimantan to West Kalimantan, from South Kalimantan to Central Kalimantan, from Southeast Sulawesi to Central Sulawesi, and from the Papua Highlands to West Papua.

For other confluence zones, BMKG notes formation in the South China Sea and extending from the Western Indian Ocean near Lampung to the southern part of Banten. The combined dynamics are said to significantly increase the potential for rainfall cloud development at the convergence lines and along wind shear.

The public is reminded to keep information on weather updated regularly to anticipate hydrometeorological disasters. Detailed information can be accessed on the official bmkg.go.id website or on the official social media account @infobmkg.

Fishermen report taking greater caution and reducing their fishing distance due to fluctuating weather conditions in recent days.

Earlier, BMKG warned of potential significant weather across Indonesia on Wednesday, 20 May 2026. BMKG Hang Nadim Batam Meteorological Station warns of possible sudden downpours in Batam today. BMKG warned of potential thunderstorms and extreme weather in Indonesia on 19 May 2026 due to three cyclonic circulations. Check your city forecast here. BMKG forecast Jakarta weather on Monday, 18 May 2026 would be light rain in the afternoon to evening.