Ticks are now a nuisance for orienteers even in Finland: “They’ve increased explosively”. Photo: Roni Rekomaa / Lehtikuva
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Tick sightings in Finland have more than doubled compared to last year, with over 115,000 reports submitted so far in 2025. The sharp rise is linked to mild, wet conditions and a warming climate that continues to favour the spread and survival of ticks across the country.
The data comes from Punkkilive, a nationwide tracking platform operated by the University of Turku and pharmaceutical company Pfizer. In 2024, the total number of tick sightings for the entire year was around 62,000.
Ilari Sääksjärvi, professor at the University of Turku’s Biodiversity Unit, said that ticks thrive when rainfall is steady and temperatures remain relatively high.
“Ticks dehydrate easily. This summer we’ve had exactly the kind of weather they prefer, not too dry, not too hot, and with regular moisture,” he said.
While dry heatwaves temporarily push ticks into hiding, short daily showers maintain the humidity that keeps them active in vegetation. According to Sääksjärvi, the taiga tick’s activity typically drops off by early July, but the more common species may remain active into November if temperatures stay mild.
Regional data shows a sharp rise in sightings in multiple parts of Finland. In Kokkola, Central Ostrobothnia, reports increased from 1,200 in 2024 to over 3,100 in 2025. In Vaasa, roughly 100 kilometres away, sightings nearly doubled from just over 1,000 to around 2,000. Inland in Seinäjoki, the number of ticks reported grew from under 500 to approximately 1,200.
Despite the surge in sightings, Sääksjärvi urged the public to approach the situation with caution rather than panic.
“People should be aware of the risks but still enjoy nature. Just remember to do tick checks after being outdoors,” he said.
With cases of Lyme disease and tick-borne encephalitis (TBE) rising, Sääksjärvi also encouraged residents in high-risk areas to get vaccinated, even if it’s already mid-July.
“If we get a warm autumn, ticks could stay active well into September or October, and isolated ticks might still be out in November,” he said.
In the long term, Sääksjärvi said Finland’s tick population has grown steadily due to changing environmental conditions, including earlier breeding seasons and a broader geographic range.
“Climate change is part of the bigger picture here,” he added.
HT
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Source: www.helsinkitimes.fi
