The next few weeks will determine the severity of the mosquito summer in Finland, as the prolonged dry spring is likely to reduce their numbers significantly.

The amount of spring water is critical for Aedes mosquitoes, said insect researcher Reima Leinonen from Kajaani, as reported by Yle. The dry conditions in most of Finland, excluding Lapland, have been exceptional in both the west and the east, with little snowfall over the winter and no recent rain.

If heavy rain arrives in the coming weeks followed by warm weather, mosquitoes could still hatch in some areas, Leinonen said. If the drought continues, some of the mosquito eggs will remain dormant and survive to the next year by skipping a season. In places that received ample snow and meltwater, mosquito numbers are likely to be normal this summer.