Vavuniya sits in Sri Lanka’s dry zone in the north or east, where the northeast monsoon from October through January is the dominant source of rainfall, in contrast to the southwest monsoon that soaks the island’s wet zone.
In Sri Lanka’s dry zone interior, the town’s rivers can rise quickly when the northeast monsoon delivers intense rainfall to typically dry terrain. Because this region’s rainfall is concentrated into a shorter, later season than the rest of the island, an intense northeast monsoon storm can produce flooding relatively quickly on terrain that spends much of the year dry, and radar helps track these seasonal rain bands as they develop. Learn more: Flash Flood Warning Signs on Radar · Open the full Rain Map