When is the peak season for dengue in Sri Lanka?

Dengue peak season in Sri Lanka seems to follow the monsoon rains very closely. It tends to show up from May to July, and again from October to January, so people often notice it around those times.

Transmission can really jump during and right after the Southwest Monsoon, spanning May through September, and also during the Northeast Monsoon from October to January. With the heavy rainfall, there is plenty of stagnant water, which becomes a kind of perfect nursery for Aedes aegypti mosquitoes to thrive. Even though travellers should use mosquito bite prevention throughout the year, extra caution is needed in these months because local case counts can rise quickly, almost suddenly at times.