The number of tick sightings in Finland has increased dramatically this year.
According to the Punkkilive website, run by the University of Turku and pharmaceutical company Pfizer, over 115,000 tick sightings have already been reported in Finland so far this year. In 2024, the total number of sightings for the entire year was about 62,000.
Professor Ilari Sääksjärvi from the University of Turku’s Biodiversity Unit said that this spring and summer have provided ideal conditions for ticks, as it has not been too dry.
"Ticks are creatures that get dehydrated easily. When there’s rain and temperatures stay relatively high, that’s the ideal weather for ticks," he said.
If a dry heatwave lasts long, ticks hide in organic debris but don’t disappear. When moisture returns, they scurry back into vegetation to hunt. If daily showers or storms occur during a heatwave, humidity stays high, and ticks remain active in the vegetation.
According to Sääksjärvi, the most active season for the taiga tick begins to taper off in early July, but the season for the common tick may continue into November, weather permitting.
Numbers vary within short distances
Tick sightings have risen nationwide, yet significant variations exist even over short distances.
In Kokkola, Central Ostrobothnia, tick sightings have risen from 1,200 last year to over 3,100 this year.
About 100 km away in Vaasa in Ostrobothnia, sightings increased from just over 1,000 last year to around 2,000 this year. Less than 100 km inland in Seinäjoki, South Ostrobothnia, sightings were under 500 last year but have climbed to about 1,200 this year.
Sääksjärvi noted that tick populations have grown significantly over the long term as Finland’s environmental conditions steadily become more favorable for them.
Breeding seasons are gradually lengthening, leading to stronger populations, while their range continues to expand further north.
"In the bigger picture, climate change is one of the factors behind this," Sääksjärvi said.
Worth getting a shot
According to Sääksjärvi, people should be aware of ticks and the health risks they pose, but sensibly — there’s no need for excessive fear.
As tick numbers rise, so do cases of Lyme disease and tick-borne encephalitis (TBE). However, Sääksjärvi said people shouldn’t let this stop them from enjoying nature.
He advises doing tick checks after spending time outdoors and encourages vaccination if you live in an area where tick-borne encephalitis is present.
Even though it’s already July, Sääksjärvi still recommends getting vaccinated this summer if you live in a risk area.
"If we have a warm autumn, the ticks could easily stay active through September and October. And if temperatures stay mild enough, you can definitely still encounter individual ticks well into November," he said.
