BMKG Warns of Heavy Rain and Strong Winds in North Sumatra on Sunday, 21 June 2026

The Meteorology, Climatology and Geophysics Agency (BMKG) has issued an early warning for communities in North Sumatra to be alert for potential extreme weather on Sunday, 21 June 2026. Moderate to heavy rain accompanied by lightning and strong winds is predicted to hit several strategic locations. Budi Prasetyo, a forecaster at the Centre for Meteorology, Climatology and Geophysics (BBMKG) Region I Medan, explained that the weather conditions in North Sumatra are triggered by atmospheric dynamics that still indicate significant potential for rain cloud growth in the region. Budi stressed that people in specific areas should increase their vigilance against the secondary impacts of this extreme weather. “Be alert to the potential for moderate to heavy rain that can be accompanied by lightning and strong winds in the southern part of North Sumatra, the eastern slopes, and the eastern coast, which can cause disasters such as flooding and landslides,” he said in Medan on Saturday (20/6). Based on the detailed weather forecast for Sunday (21/6), average air temperatures are expected to range from 14 to 33 degrees Celsius, with humidity levels reaching 67 to 99 percent. Winds will generally blow from the South to Southwest at speeds between 5 and 25 km per hour. Christen Ordain Novena Marpaung, a forecaster at the BMKG Class II Maritime Meteorology Station in Belawan, added a warning regarding water conditions. From 21 to 24 June 2026, several waters in North Sumatra are at risk of being hit by high waves due to wind patterns reaching speeds of 25-30 knots. The BMKG has mapped two categories of wave risk in North Sumatra’s waters. The public, especially fishermen and sea transport operators, are urged to pay attention to shipping safety risks and to continue monitoring weather information updates from the official BMKG weather forecast channels.